It was March 2020, deep in the pandemic. In the general internal medicine unit of a downtown hospital, resident Neha Puri (MD ’19) plunged into providing care to patients with severe COVID-19 symptoms. One patient — a man in his 80s with a lung injury — had just died. Puri had to FaceTime his family members across the continent to let them know about his death.

By Hilary Caton

Once finished, she rushed through the hallway to make it to the call room before her tears started. Even today, more than three years later, the man’s death is one of the enduring memories of Puri’s pandemic experience.

“I don’t think we — heath care providers — have had time to process what happened. I think we’ve just moved on. You have to do that in the line of work that we do,” says Puri, who is now a general internal medicine fellow at the Temerty Faculty of Medicine’s Department of Medicine.

Her words echo those of many front-line clinicians whose stream of patient consults and daily rounds haven’t stopped or stemmed. Meanwhile, the effects of the COVID-19 pandemic are still being uncovered. And, what isn’t known yet is how these memories will affect us. 

There’s also the complicating factor that recollections of life during COVID-19 — and the lockdowns — have taken on an elusive shape for many, even though the ramifications persist. Some say the memories of washing their groceries and queueing for toilet paper feel like they transpired far longer ago than the three calendar years that have elapsed since WHO declared COVID-19 a pandemic.

Why are some people forgetting what was such a profoundly traumatic time? Some of this forgetting might be the nature of memory itself. 

FORGETTING AS A FORM OF LEARNING 

Instead of seeing forgetting as bad, like misplacing or losing important information, it requires a shift of perspective. The act of forgetting could actually be good for our cognitive abilities, say researchers.

“Generally, we forget things because remembering absolutely everything could be a source of confusion and a waste of energy,” says Paul Frankland, a professor in Temerty Medicine’s Department of Physiology and Institute of Medical Science.

Forgetting is a necessary process for our brain to eliminate irrelevant information and learn new information, says Frankland. In fact, it has a name – neurogenesis. Frankland and Blake Richards made headlines around the world in 2017 when they published a study that says the process of forgetting is beneficial to overall decision-making. In the study, the researchers found that the interaction between remembering (known as persistence) and forgetting (known as transience) allows for smart decision-making in situations in rapidly changing circumstances. Their study argues that forgetting enhances a person’s flexibility by reducing the influence of potentially old (and possibly useless) information on decision-making.

“We encounter a lot of information in our lives, and the vast majority of it is irrelevant to our everyday decisions,” says Richards, an associate professor at McGill University’s School of Computer Science and the Montreal Neurological Institute. 

When it comes to processing memories, Richards says our brains can forget pandemic-related details, if we (potentially wrongly) perceive that they no longer apply to our lives. The important takeaways are broad-stroke ideas such as the importance of listening to public health officials and taking our collective responsibility seriously, says Richards.

“There is a process when we have to recall information to make a decision. The more you remember everything, the harder that process is going to be of sorting through to the relevant information,” he says.

THE MECHANICS OF MEMORY

Sheena Josselyn, a professor in Temerty Medicine’s Department of Physiology, says the way our brains form memories can explain wildly different recollections of the pandemic. Some forgetfulness is natural, and depends on a person’s unique circumstances.

“We’ve now stopped defining things as pre-COVID and post-COVID, so that signals to me that we are losing this big collective memory of the pandemic,” says Josselyn, a senior scientist at The Hospital for Sick Children.

The reason why some people have started to forget what life was like during the pandemic has to do with how our brains process and store memories, she explains. The human brain has a three-step neurocognitive process for forming memories. That three-step process means that to recall an event, a person must encode the memory, consolidate it and then be able to retrieve it later. 

Excitatory neurons are particularly active when something important happens to a person, says Josselyn. Memories with emotional resonance, like the one Puri recalls, would be stored in amygdala. This is why we often remember events that have significant feelings involved — milestone moments such as births, weddings and deaths. It also helps explain why health care workers who confronted life-altering situations during COVID have very vivid memories of the pandemic.

For others who were in lockdown at home and mired in a similar routine every day, their pandemic experience may have felt mundane, and their memories of it could be fleeting. 

“With COVID, there was nothing to anchor even the most basic memories in a timeline. Every day seemed very similar. So, it was hard to sort out how much time had elapsed,” Josselyn says. “When we lose the time and place, memories tend to get jelly-like, and they become hard to tie down.”

These jelly-like memories can get harder and harder to recall as time goes on, she says. Meanwhile, a traumatic memory — such as those experienced by people with post-traumatic stress disorder (PTSD) — can become more intense over time if a person replays the traumatic memory in their mind, says Josselyn.

“I could imagine that for some people, memories related to the trauma of the pandemic, and whatever happened to them, could be very intrusive,” she says. 

People, especially those from historically and currently oppressed groups, may come away from encounters in the health system feeling more harmed than helped

WHAT THIS MEANS FOR HEALTH CARE WORKERS

During the pandemic, the strong relationship between mental health, health care workers and caregiving cannot be overstated. 

“What we saw was a lot of health care workers extremely afraid of bringing the virus home. That is still talked about. People were traumatized,” says Rima Styra, an associate professor in Temerty Medicine’s Department of Psychiatry. “Even now, we’ve found health care workers have highly prevalent post-traumatic stress symptoms, symptoms of anxiety and symptoms of depression.”

The figures are grim. In a recent JAMA study looking at approximately 34,000 Ontario physicians, the pandemic was associated with a substantial increase in outpatient care for mental health and substance use, in this group. Demands for care went up 13 per cent, on average, during the first 12 months of the pandemic, compared with the 12 months leading up to the pandemic.

Styra also published research in 2022 that explored the relationship between emotional support, perceived risk and mental health outcomes among health care workers. She found that health care workers who felt unsupported in their work had higher odds of experiencing moderate and severe symptoms of anxiety, PTSD and depression. Feeling unsupported led to burnout, staff shortages and workers leaving the health care sector altogether. 

“You get to know your patients and their families, and you really become involved in their lives in a way. You try to help, and sometimes the outcomes aren’t all that great. That was tough on health care workers,” says Styra.

ACKNOWLEDGING PROBLEMS

COVID-19 also highlighted embedded social inequities.

“I think that we still have a lot of work to do,” says Chase McMurren (PGME ’13), an assistant professor in Temerty Medicine’s Department of Family and Community Medicine and the theme lead for Indigenous health in the MD program. “People, especially those from historically and currently oppressed groups, may come away from encounters in the health system feeling more harmed than helped.”

In a 2021 Public Health Agency of Canada report, some of the First Nations, Inuit and Métis participants said that because of past experiences of systemic racism in health care, they felt uncomfortable accessing testing or health care services, and even more so during the pandemic. The report also states that institutional and systemic racism in health care and the allied health professions continues to be one of the biggest issues that many Indigenous peoples face.

A 2023 study by researchers including Modupe Tunde-Byass (PGME ’04), an associate professor in Temerty Medicine’s Department of Obstetrics and Gynaecology, found that the pandemic resulted in disproportionate challenges among racialized communities in Canada. The study acknowledged the deeply rooted mistrust that Black communities have for the health care system, which stems from a historical fear of being experimented on or offered ineffective treatment by health care institutions.

Racialized communities suffer from a significant lack of access to medical and mental health services, and have precarious and high-risk employment. The report also said that racialized communities lacked access to information about the pandemic. Approaching patient care and training overall with a trauma-informed lens is beneficial to all patients, but especially to those who distrust the health care system based on historical colonial trauma, says McMurren.

RESPONDING BETTER TO TRAUMA

Addressing the COVID-19 pandemic effectively also means acknowledging the need for trauma-informed learning at Temerty Medicine, as well as the importance of providing trauma-informed care for patients in general.

Shari Thompson-Ricci, Temerty Medicine’s equity, diversity and inclusion program coordinator and educator, is helping create workshops on trauma-informed learning environments for Temerty Medicine faculty and leaders, with Reena Pattani (PGME ’13 & ’14) and Allison Crawford (PGME ’05). 

Thompson-Ricci says trauma-informed medical education taps into the six principles of trauma-informed approaches — safety; trustworthiness and transparency; peer support; collaboration and mutuality; empowerment and choice; and cultural, historical and gender issues. The hope is that health care providers embody trauma-informed care and incorporate it into their practice, thereby creating a safer space for patients, the patients’ family and the entire health care team.

“The approach is multifaceted because it’s not limited to the health care provider and the patient, but it is also important to focus on applying the approach to interprofessional team collaborations, which can enhance patient care and improve health outcomes within the hospital,” says Thompson-Ricci. Training current and future doctors to be more trauma-informed is “extremely helpful,” she says.

“If we are being more trauma-informed and intentional about how we are educating our learners who are future doctors, if we have leaders within the medical school modelling this type of practice, it is absolutely going to help us in the long run, not just when we’re facing a pandemic,” she says.

REFRAMING MEMORY

Styra believes that not all memories of the pandemic have to be negative. For one, the pandemic created an emphasis on the well-being of health care workers, she says.

“Every kind of support is out there now for health care workers — individual support, group support, peer support and virtual support. There’s a tremendous number of options available. That didn’t happen before the pandemic,” she says.

Of the more than 3,800 health care workers Styra surveyed in her study, 77 per cent received emotional support from family, 74 per cent from friends and 70 per cent from colleagues. Having all three avenues of support makes a difference, she says. 

For Puri, surviving the relentless march of the pandemic meant relying on colleagues and decompressing with people outside of the profession. A happy memory for her was the day when the Moderna and Pfizer vaccines came out — a “turning point” she celebrated with joyful tears on the phone with her sister.

“It had felt like we were going to war together. We could finally see some light at the end of the tunnel,” she says. Puri is now at the Dalla Lana School of Public Health earning a master’s degree in health practitioner teacher education. The dark memories of the pandemic — and 26-hour calls — didn’t put a dint in her love of medicine. If anything, they reinforced it. 

“They’ve taught me the importance of humility in medicine, and to embrace the attitude of lifelong learning,” she says. “The pandemic taught me to take it one day at a time, and to know that we’ll figure it out together. There’s so much to know. Lifelong learning is something every physician should embody.” •

Why It’s Hard to Shake Medical Misinformation 

By Blake Eligh

Melanie Henry (PGME ’14 & ’15) is a staff physician with Oak Valley Health in Markham, Ontario. In her busy practice, she has more than 900 patients, including many families with young children. As part of her practice, Henry often raises the topic of infant immunizations with patients, such as routine vaccinations for measles, mumps and rubella. What she sometimes hears back are parent worries.

“Often, patients have already done their research online. They know their favourite websites and may be convinced that the vaccines could be harmful to themselves or their children,” explains Henry, vice-chair, community and partnerships with the Temerty Faculty of Medicine’s Department of Family and Community Medicine. “In the moment, there’s nothing I can say to dissuade them from this idea. Giving them a pamphlet from the government won’t move the needle much.”

What Henry is encountering in these conversations is misinformation and fear. It’s a potent combination. Fear can amplify the significance of information that aligns with your deepest anxieties, and embed that information in your memory.

The process through which the brain learns and stores information is called “long-term potentiation” or LTP. It’s a central research focus for neuroscientist Graham Collingridge, a Temerty Medicine physiology professor and the director of the Tanz Centre for Research in Neurodegenerative Diseases. There, Collingridge delves into how memories form at the molecular level in the brain, which he describes as “the most complex machine in the known universe.”

During memory formation, neurons communicate with one another through synaptic connections. Frequent activation strengthens these connections — just as how repetitive weightlifting builds and fortifies muscles. When synapses undergo strengthening through LTP, they become more effective at transmitting information and facilitate the brain’s ability to create and retain memories. Fear can intensify these synaptic connections by prompting the amygdala and the hippocampal regions of the brain to work together to form emotionally charged memories. The stronger the connection, the more likely it will endure over an extended period of time. 

“Our memories are associative,” Collingridge says. “We are bombarded with billions of pieces of information and we have to select what’s important. If something happens and it’s particularly pleasurable or fearful, we are more likely to commit it to memory because it’s going to be important for survival.”

Fear may help encode information into memory, he continues. Fear of the unknown can also drive people to seek out information, and when the information they find isn’t reliable, it can lead to adverse health outcomes. Take an announcement earlier this year from Robert Califf, the United States Food and Drug Administration’s commissioner. Califf cited misinformation as one of the primary factors impacting the lifespan of Americans, alongside income, education, race and ethnicity. The U.S. now ranks last among high-income nations for life expectancy, with figures three to five years lower than comparable nations. 

It’s about understanding and asking,
‘What do you think and why?’ 

Califf highlights the internet and the ready availability of often unreliable health information significantly influencing people’s decisions, leading them to make unhealthy choices, such as forgoing vaccinations. In Canada, a separate study involving more than 1,800 Ontarians revealed that “more than half of the participants reported encountering misinformation when seeking information about COVID-19,” and many reported at least one challenge with their information-seeking process.

Teasing out the role of social media in the lightning-quick spread of health misinformation is an evolving area of study. During his psychiatry residency in 2021, Anthony Yeung noticed an uptick in patient requests for assessment related to attention deficit hyperactivity disorder (ADHD), which appeared to be driven by social media. 

The observation prompted Yeung (PGME ’21) and colleagues to kick off a study looking at ADHD information on TikTok, an international video platform with 1 billion daily views of user-generated content delivered to its audience through the platform’s algorithm.

After reviewing 400 of the most popular TikTok videos tagged with the #ADHD hashtag, the researchers discovered that approximately half of the videos contained misleading information about ADHD symptoms, diagnosis or treatment. They also found 90 per cent of these videos were created by the general public, and just 10 per cent came from trained health care providers. As Yeung explains, the audience reach of each video they studied was remarkable — averaging 2.8 million views and 30,000 shares.

“In many of the videos, there were no caveats or recommendations to talk to your doctor,” notes Yeung, now a clinical instructor at the University of British Columbia. “From a clinical perspective, many of the symptoms the creators described were so non-specific that while it could indicate a person had ADHD, it could also easily describe symptoms of another psychiatric disorder, or it could be another medical issue like sleep apnea,” he says. “In a 10-second video, there’s not a lot of room for nuance.”

While Yeung acknowledges that the internet has been “net positive” for raising awareness of mental health issues, he emphasizes that health care practitioners need to enhance their digital literacy to provide effective patient care.

“ADHD has entered the public consciousness, and it deserves attention from the medical community to talk about this more,” he says. For Yeung, the discovery underscores the influence of social media in people’s health care decisions, and whether they opt to consult a trained professional. 

“The amount of content we are consuming comes at such a fast pace. It can be hard for the average person — and the average clinician — to parse what’s good information and what’s bad information,” he says. “People might form their perceptions of ADHD based on what they see in online videos. The clinical reality is often quite different.”

For Henry, educating patients who express vaccine hesitancy requires patience and time. That means committing to understanding her patients’ perspectives and how they came to be their beliefs. This way, Henry can engage them in an effective, compassionate way while providing clinically sound medical advice. It also means connecting with patients on a personal level.

“Once I had kids, I completely understood why parents are concerned about injecting things into their children’s bodies, and the feeling that you are entirely responsible for them,” she says. Those worries can extend to other decisions, such as choosing between formula or breastfeeding, or introducing solid foods, she adds. She keeps the door open with patients by grounding her approach in curiosity, respect and trust. A hardline approach doesn’t change minds, says Henry.

“As a family doctor, these are the conversations, stories and interactions that I want to be having with people. If I understand where they’re coming from, it becomes a starting point for negotiation. It’s about understanding and asking, ‘What do you think and why? Is there a compromise — an age where you might be more comfortable to revisit this? Is it OK to bring this up next time and see what you’re thinking?,’” she says. “As a clinician, I want to build a relationship with the family and in the end, they almost always choose to have their children vaccinated.” •

By Dan Falk 

With young children and parents in their late 80s, Alex Mihailidis finds himself sandwiched between two generations who depend on him for care. 

“Managing all of that, together with my job here at the university, sometimes becomes very difficult,” says Mihailidis, a professor in the Temerty Faculty of Medicine’s Department of Occupational Science and Occupational Therapy, and an associate vice-president for international partnerships at the University of Toronto.

The number of people living with dementia is growing, and rapidly at that. Today, the condition affects almost 600,000 Canadians. By 2030, that figure will grow to almost 950,000, according to the Alzheimer Society of Canada.

Dementia — which the society defines as “a set of symptoms caused by specific disruptions to healthy brain functioning that reduce a person’s ability to perform everyday activities” — leads to attention difficulties, memory problems, behavioural and mood shifts, and other issues. 

It can cause people to forget when they ate their last meal, where they live and who their loved ones are. For Mihailidis, his family experiences have helped drive the overall goal of his research. He’s working with a team to create a system called COACH (Cognitive Orthosis for Assisting with aCtivities in the Home).

Developed at the Intelligent Assistive Technology and Systems Lab, COACH is a prototype of a “smart home system” that can help people with dementia perform everyday tasks with a greater degree of independence. It uses cameras and other sensors to track an individual as they go about activities around their home, and can provide verbal or visual reminders as needed. 

“Whether it’s washing their hands, brushing their teeth or making a meal, the system can provide the assistance and support that that person might need, just like a caregiver would,” says Mihailidis, who is also a professor at U of T’s Rehabilitation Sciences Institute and its Institute of Biomaterials and Biomedical Engineering, as well as the KITE Research Institute.

He says COACH’s goal is to allow older adults to spend more time at home and with their families, rather than in hospitals or care homes. COACH can also assist caregivers, many of whom may be experiencing stress and mental health challenges as a result of their responsibilities. 

Mihailidis mentions a colleague who installed an electronic medication device in his mother’s house, which lets him know that she has taken her medication. “He used to call her and start by saying, ‘Mom, have you taken your pills?’ Now he can start by saying, ‘Hey Mom, how’s your morning going?’ So instead of talking to her like a patient, he can talk to her like she’s his mom again,” he says.

COACH is still being tested, but Mihailidis has high hopes for the project. His ambition is to create a more advanced version of COACH that employs social robots that can speak, play a video, use gestures and make eye contact with the user. “That’s the latest version of the project that we’re testing,” he says. “We hope one day they will be able to play a role in the lives of older adults so they can remain at home, and stay healthy and well. That’s my ultimate goal.”

Other U of T researchers are also working to leverage technology to address issues related to memory disorders, such as dementia and Alzheimer’s disease. For geriatric psychiatrist Andrea Iaboni (MD ’06, PGME ’13), the focus is on wearable technology — such as a wrist device that a patient would wear to collect health data in real time.

“People with dementia can exhibit neuropsychiatric symptoms, and what we call ‘responsive behaviour,’” explains Iaboni, an associate professor in Temerty Medicine’s Department of Psychiatry and a senior scientist at the Toronto Rehabilitation Institute (TRI). “These are behaviours that are in response to some need or some trigger in the environment. And that can put people with dementia, and others, at risk.”

To track these potentially harm-causing behaviours, Iaboni and her colleagues at TRI’s specialized dementia unit are developing a device that tracks such variables as movement, heart rate and body temperature. Data from the device can be used to develop a profile of a person with dementia, which can then be used to improve their care. 

Iaboni believes that there’s a lot of data in health care that scientists have yet to take advantage of. “There are cameras in health care all over the place — in hospitals, in the common areas of nursing homes,” she says. “But a lot of these cameras just feed video to a monitor, and that’s it. The data never gets used.” 

Technology can play a crucial role in detecting diseases such as Alzheimer’s, says Sharon Cohen (DSP ’79, MD ’86, PGME ’91), the medical director of the Toronto Memory Program. Cohen has been working with the medical imaging company RetiSpec that has developed a retinal scan that can detect the signature of amyloid in the retina. Amyloid is a toxic protein that accumulates in the brain in Alzheimer’s and is present in the earliest stages of the disease. 

For the patient, the scan is similar to an ordinary eye exam, except that the system uses a camera that records light from a broad swath of the electromagnetic spectrum and uses AI to analyze the resulting data, says Cohen. At present, Alzheimer’s is typically diagnosed via positron emission tomography (PET) scans or a spinal tap. Even though there’s no cure for Alzheimer’s, early diagnosis is still valuable, she says. 

“Knowing what one’s dealing with and being able to plan ahead is helpful for both patient and family,” says Cohen. New technologies are continuing to be developed globally to help manage dementia care, agrees Sinjan Ghosh (PGME ’23), who is based at Fortis Hospital in Kolkata, India, and recently completed a clinical fellowship in behavioural neurology at Baycrest. While in Toronto, Ghosh worked with Morris Freedman, a neurology professor at Temerty Medicine and the medical director of Baycrest Health Sciences’ Pamela & Paul Austin Centre for Neurology and Behavioural Support. They treated patients with varying degrees of dementia, including those with behavioural issues like agitation and aggression.

Ghosh says AI tools are being created to read emotions and alert a physician if the patient shows symptoms of a mood change, such as depression, Ghosh says. Even so, he sees these technologies as aiding physicians and caregivers, not replacing them. “AI is not going to replace human beings,” Ghosh says. “But, a physician or a scientist who is proficient and has a sound knowledge of AI is going to replace someone who doesn’t have that knowledge.”

When it comes to improving dementia care, for Mihailidis, the matter is pressing. “As our population ages, we will need to implement better resources to care for people with dementia. They deserve it, and we must start to deliver,” says Mihailidis. •

Can we stop memory loss?

By Lauren Vogel

Forgetful. Distracted. Dazed. Struggling to find words. Trapped in a constant state of déjà vu. A brain in slow motion. A head stuffed with rags.

People with brain fog vividly describe a common constellation of debilitating impairments in memory and executive function — the basic mental processes required to prioritize, focus, and follow through on thoughts and tasks. But brain fog isn’t a clinical diagnosis as much as a colloquial catch-all for the cognitive difficulties that cut across a wide range of conditions — from cancer to long COVID. And despite growing recognition, these cognitive difficulties can be poorly understood by clinicians who lack adequate testing or treatments to tackle the problem. 

“In patients with breathlessness, we might look to the lungs, or with a painful calf to blood clotting,” writes Laura McWhirter, a consultant neuropsychiatrist and clinical research fellow at the University of Edinburgh, in a 2023 study. “But where in the brain might we look for the source of a fog?” 

Research at the Temerty Faculty of Medicine is cutting through the haze — from pioneering work tracing the cognitive fallout of anesthesia and chemotherapy to the hunt for treatments for Alzheimer’s disease and long COVID. 

Beverley Orser (PGME ’87, PhD ’95), like many of her peers in anesthesiology, initially struggled to believe that the same miracle drugs that block the pain of surgery could have lasting cognitive impacts on patients. 

“For decades and decades, we’ve known that sometimes our patients weren’t quite right after surgery,” says Orser, the chair of Temerty Medicine’s Department of Anesthesiology & Pain Medicine. Yet, it was widely assumed that any effects of anesthesia cleared once the drugs left the body. Perioperative neurocognitive disorders — ranging from short-term delirium to lasting cognitive decline — affect roughly one in four surgical patients one week after surgery, and one in 10 patients up to three months later. 

Orser’s own mother struggled to remember visitors and manage her medications for weeks after a hip replacement, despite showing all appearances of an exemplary recovery. “Subsequently, she developed major cognitive decline,” Orser recalls. “It became apparent to me that even someone who is seemingly doing well can have quite a major change in brain function after anesthesia and surgery.”

After a series of studies in the early 2000s revealed that the anesthetic ketamine could improve symptoms of depression long after the drug left the body, Orser refocused her lab at the University of Toronto to better understand the mechanisms at work. “We were surprised to find that anesthesia triggered an overexpression of memory—blocking receptors in the brain in animal models,” Orser says. 

Changes in either the number or function of these α5-GABAA receptors cause profound learning and memory deficits, she explains. “Later, we found that inflammatory factors also drive an overexpression of these receptors, while drugs that inhibit them improve cognitive behaviours,” she says. 

These findings led to the development of a new class of drugs for restoring memory loss after surgery and pointed to a new “druggable” target for the treatment for other cognitive disorders. “We’ve looked at traumatic brain injury, and there’s some evidence that overactivity of α5-GABAA likely contributes to changes in plasticity that underly memory deficits,” Orser says. Other labs have found similar links with stroke, depression and Alzheimer’s disease.

Like anesthesia, cancer treatments are linked with a wide range of cognitive deficits commonly known as “chemo brain.” 

“It affects memory, attention, ability to focus, your processing speed — all things that make you feel like you’re not quite yourself,” says Melanie Sekeres (PhD ’12), an assistant professor in the University of Ottawa’s School of Psychology. As many as three in four chemotherapy patients experience these deficits that in some cases can last for decades. While earning a PhD at U of T, Sekeres collaborated with Gordon Winocur, then a professor in Temerty Medicine’s Department of Psychiatry. They worked on one of the first studies to shed light on how cancer and chemotherapy cause cognitive impairment in animal models. 

They found three distinct brain changes at play. The first is an immune reaction to the cancer itself that triggers inflammation, affecting brain function. Then, chemotherapy causes a reduction in the generation of new neurons in the hippocampus, a brain structure critical to forming and recalling memories. 

Finally, both chemotherapy and tumour growth cause significant shrinking of both the hippocampus and the frontal lobes, another structure involved in memory. 

Sekeres notes that the problems with focus and other executive functions reported by patients receiving chemo appear similar to the frontal lobe dysfunction seen in aging adults and those with dementia.

“It’s likely that some or many of the same cellular mechanisms, for example neuroinflammation leading to cellular dysfunction, are co-occurring in many of these conditions,” she says. Sekeres is now studying chemo brain in breast cancer survivors, hoping to untangle potential variables that may affect a person’s vulnerability. Among other factors, she’s asking patients about their stress, sleep quality and exercise level. 

“A lot of these psychosocial and environmental factors may predispose or protect them,” she says.

Recent dementia research highlights the potential for using biomarkers to pinpoint treatments for cognitive symptoms. One of the most distressing of these symptoms is agitation, which can include physical and verbal aggression, and affects up to 88 per cent of people with Alzheimer’s disease. Doctors often prescribe antipsychotics to manage agitation, but these drugs carry serious risks of falls, heart problems, stroke and even death.

Krista Lanctôt (MSc ’89, PhD ’98), a professor in Temerty Medicine’s Department of Psychiatry and Department of Pharmacology and Toxicology, sought a safer alternative treatment in nabilone, a synthetic version of the tetrahydrocannabinol found in cannabis. “Our brains are already wired with cannabinoid receptors, and the brain makes cannabinoids that help with inflammation and oxidative stress,” explains Lanctôt, the Bernick Chair in Geriatric Psychopharmacology. 

However, she says that, “as the brain deteriorates in Alzheimer disease, there’s a theory that changes to this endocannabinoid system contribute to cell death.” In addition to potentially providing a calming effect, nabilone may also take advantage of this natural system for fighting inflammation and oxidative stress. 

In a small randomized controlled trial, Lanctôt and her team found that nabilone was much better than a placebo in decreasing agitation. They also looked at biomarkers in patients’ blood to determine who might benefit the most from the treatment. They found that a higher level of inflammation and oxidative stress were linked with more severe agitation. Patients with a higher level of inflammation were more likely to respond to treatment with nabilone, and their inflammation decreased with treatment. 

The findings point to a new way to tackle agitation by targeting underlying inflammation, says Myuri Ruthirakuhan (PhD ’19), a postdoctoral fellow at the Sunnybrook Research Institute who led the biomarkers portion of the study as part of her doctoral work at Temerty Medicine. “We were able to show there is not only a clinical benefit, there’s a biological benefit as well,” Ruthirakuhan says. 

Lanctôt and her colleagues are now undertaking a larger trial of 200 people to confirm the results.

Inflammation is also a likely culprit in long COVID. As many as 10 to 30 per cent of people infected with SARS-CoV-2 report ongoing symptoms after their initial illness. 

Brain fog and fatigue are among the most common and disabling of these symptoms, says Roger McIntyre (PGME ’98), a professor in Temerty Medicine’s Department of Psychiatry and Department of Pharmacology and Toxicology. “These cognitive deficits may be related to so-called ‘friendly fire,’ where the immune system takes care of the virus but leaves collateral damage or prolonged inflammation, which we know can impact brain function,” says McIntyre, the head of the Mood Disorders Psychopharmacology Unit at University Health Network. 

At the same time, the virus may attack the brain directly by killing cells and indirectly by damaging blood vessels, compromising the brain’s energy and oxygen supplies. The potential role of inflammation in long COVID prompted McIntyre to investigate the widely available antidepressant vortioxetine as a possible treatment. Previous studies have shown that vortioxetine can improve cognition regardless of whether a person has depression, McIntyre explains. 

“There is a rich science showing this drug is potentially anti-inflammatory,” he says. In a recent trial of 200 people with long COVID, McIntyre initially didn’t see any difference in cognition between those who received vortioxetine for eight weeks and those who received a placebo. 

However, on a closer look, those receiving the antidepressant reported significant improvements in their quality of life. Also, participants with an elevated marker of inflammation showed significant improvements in their cognition while taking the drug. McIntyre says his findings, which are not yet published, add to evidence supporting the role of inflammation in long COVID. 

“Whatever this brain fog is, it is amenable to therapeutic intervention,” he says. “There’s a lead here and it will have to be replicated. But what this tells me is that maybe having long COVID is not a lifetime curse.”

Can immune memory protect us from the flu?

By Erin Howe

It’s been about 80 years since the first flu shot was developed and since then, researchers have been searching for more powerful and effective vaccines. Vaccines, a mighty tool for preventing or mitigating illness from the flu, are particularly valuable when they’re well matched to the flu strains that circulate the season they’re administered.

But what if instead of being able to defend people against three or four strains of influenza, a vaccine could provide broad protection from all strains of the virus?

Researchers at the Temerty Faculty of Medicine are exploring whether the key to creating a universal flu vaccine could be immune memory; that is, boosting the body’s ability to recognize bugs it has fought before and arming the immune system with stronger tools and sharper surveillance. 

Infection Prevention and Control Canada estimates that influenza kills about 3,500 people annually, making the flu one of the country’s top-10 causes of death. According to WHO, about 290,000 to 650,000 people around the world die from flu viruses each year. White blood cells called “T-cells” and “B-cells” are key players in keeping infectious invaders from wreaking havoc on our health. 

Viruses like the flu contain antigens that can be recognized by the body’s immune system. When we encounter these micro-organisms, our B-cells make antibodies, the proteins that help fight off infection. The antibodies bind onto the antigens; if they can do this in a way that prevents the antigens from attaching to the cells, they can completely block infection. 

They also call in reinforcements from other immune cells to neutralize the micro-organism. At the same time, T-cells recognize the influenza antigens hidden inside the infected cells and kill the infected cells to limit the spread of infection. After completing this mission, B-cells and T-cells remember their enemies, such as influenza, and are ready to battle them again in the future. Many vaccines work by stimulating an antibody response — courtesy of B-cells — to a virus. But like a shapeshifter, influenza mutates quickly to evade even the strongest antibodies. T-cells, however, recognize viruses no matter how they may change. Within a few days of spotting their foe, T-cells spring into action to multiply and knock out infection. As they eliminate their enemy, T-cells ramp back down again. The T-cells that are left over when the immune system returns to baseline are memory T-cells, or lymphocytes. When the surviving lymphocytes see an intruder like the ones they’ve defeated before, they know what to do to knock it out. 

Karen Yeung, a PhD student in Temerty Medicine’s Department of Immunology, is exploring how a type of lymphocyte called CD8 T-cells — or killer T-cells — can persist to clear infenction.

“It’s important to have these killer T-cells in the lung tissue because that’s where the infection was. I want to know how to raise the baseline of these killer CD8 T-cells and help them stay in the airways,” says Yeung. Yeung focuses on how a signalling molecule called “4-1 BB ligand” and “receptor 4-1 BB” communicate to help immune cells move into the memory stage and how this helps them stay in the lung tissue. 

Yeung’s supervisor, Tania Watts, a professor in Temerty Medicine’s Department of Immunology, leads a group working to find ways to harness the power of T-cells and lay the groundwork for them to help fight viral villains in new vaccines. Her lab is working to determine how to generate a long-lived immune response in the lung’s mucosal surfaces to one day provide protection with a T-cell vaccine. To do this, the team is studying a group of molecules called the “tumor necrosis factor receptor family.” There are about 30 members of this receptor family, and some may control how many T-cells persist in the lung during a flu infection.

“Lymphocytes disappear from the lung over time, which might be why there isn’t long-term protection from influenza. Is it because the environment in our lungs isn’t conducive to keeping the lymphocytes there? Or would having lots of lymphocytes in our lungs cause a harmful amount of inflammation?,” asks Watts, who holds the Canada Research Chair in Anti-Viral Immunity. 

“We want to find out how to get a long-lived immune response in the lung’s mucosal surfaces. Even if we couldn’t completely prevent the flu, if we can minimize the severity, we could save a lot of lives. And a T-cell vaccine would do that,” she says.

While Yeung and Watts explore how to boost T-cells’ superpowers, Aaron Reinke takes another approach to immune memory. Reinke, an associate professor in Temerty Medicine’s Department of Molecular Genetics, is studying how the fungus microsporidia infects a microscopic nematode worm called “Caenorhabditis elegans” or “C. elegans.” 

Microsporidia are single-cell parasites that use a harpoon-like appendage to transfer their DNA into their host cells. In addition to infecting nearly all types of animals, many species of these parasites can also make humans sick. Through their research, Reinke’s team is learning how immune memory is passed from one generation to the next. 

Over a hundred years ago, scientists first observed the phenomenon of immunity being passed from parents to offspring in lab mice. Then about 20 years ago, they observed it in invertebrate systems like the nematodes that Reinke studies today. As Reinke explains, since nematodes don’t have antibodies, there must be another mechanism working to provide them with protection from the parasitic infection. 

Reinke’s lab has shown that infecting the worms with microsporidia creates resistant offspring because there are molecules that prevent the parasite from being able to invade the host cells. Now, they want to identify what generates that immunity and how that information is communicated. 

“By looking closely at C. elegans, we can start to understand how immunity is passed down from one generation to the next. Potentially, some of those mechanisms could be relevant in the human immune system. It’s still early, but we’re learning,” says Reinke. 

Why does scent evoke strong memories? 

By Sadaf Ahsan

When I picture my mom, I picture her in her garden, plucking dead roots, planting vegetables, admiring her marigolds and tulips. I see her hands stained with dirt, pricked by thorns. 

When I picture my mom, I also see her in her kitchen, grinding peppercorns, marvelling at her beautiful home-grown jalapenos, kneading rotis. I see the perspiration on her brow and her nose twitch as she takes in the nostalgic smell of her own mother’s recipes. 

When I picture my mom, I see someone whose image I can instantly conjure up not just by seeing her favourite flower or cooking her most beloved dish, but from all of the smells she surrounded me with since I was a child: spice and spruce, and the sweat of her hard work. 

In early 2020, I travelled across France to celebrate my 30th birthday and decided to bottle the scent that would forever remind me of my mom so I could never forget her. With a friend, I made a pit stop on the French Riviera, in Grasse, a small town considered to be the perfume capital of the world. 

We visited Galimard, a renowned perfumery that was established in 1747. There, we visited a vibrant studio where it seemed that every scent imaginable was at our fingertips. Galimard’s world-class perfumers told us to choose what spoke to us, mix it all together and, with a little guidance from them, we’d have our own one-of-a-kind scent.

I labelled mine “Saroash” — my mom’s maiden name. It features notes of cardamom, peach, patchouli, sandalwood and a whole host of odd fellows. Each fragment came together to paint the picture I never want to forget: my mom, in the summer, happy. An aromatic portrait.

But how could I paint this picture just through scent? How did the association between smell and memory come to be?

To put it very simply, explains Afif Aqrabawi, who studies scent and memory, memory is a set of cells that become active from an experience. The cells can be reactivated — or recalled — when you encounter a cue that resembles or reminds you of that experience. 

“Olfaction is arguably the most important sense because of the fact that it gives us everything we need to know about where there’s food, where there’s potential mates, where there’s a potential predator,” says Aqrabawi, a neuroscientist at the Massachusetts Institute of Technology. “It’s very informative, even if we don’t appreciate that informative value because we’re visual creatures.”

He says the hippocampus, which is key in this process, functions as a kind of organizer of memories. Aqrabawi suggests imagining the hippocampus as a librarian and your memories as books. The hippocampus, then, is cataloguing the books and generating an index. It’s the amygdala, meanwhile, that emotionally processes what’s happening.

By way of an illustration, he asks you to imagine that you’re walking into a bakery, and you smell fresh butter croissants. This experience activates a certain set of neurons in your brain. If this same set of cells is reactivated the next time you smell a butter croissant, that is an instance of memory recollection at work. Cues that can trigger a memory can be smell, sound or an image. 

In fact, adds Aqrabawi, “You never really forget anything, even though you sometimes don’t have conscious access to it. You encode every experience in your daily life.” 

Our scent memory is stronger than our visual memory thanks to the direct anatomical connection between the hippocampus and the olfactory system, which is where a smell first heads to in the brain. When it comes to other senses — like when you see, touch or hear something — that information first goes to the thalamus, before heading to the hippocampus and the amygdala. 

Yvonne Chan (MSc ’98, MD ’02, PGME ’06 & ’07), an associate professor at the Temerty Faculty of Medicine’s Department of Otolaryngology Head and Neck Surgery, says her patients present with different conditions that affect their sense of smell.

“Some of my patients range from not having any smell and that not affecting them at all; whereas for others, the loss of smell is devastating. It’s very dependent on your livelihood. If you’re a chef or a sommelier, someone who needs smell for your daily living, you need to be able to smell smoke or if food has spoiled. Everyone’s different,” says Chan, who is also the otolaryngologist-in-chief at St. Michael’s Hospital, Unity Health Toronto.

She recalls having one particular patient who lost her ability to smell due to nasal polyps and chronic sinusitis. The patient began to avoid regular dinners with friends because she could no longer fully enjoy the meal. (Between 75 and 95 per cent of what we taste is believed to be rooted in our sense of smell, so the loss of this sense can greatly affect our eating habits.) 

The patient eventually started isolating herself, which led to depression. She ended up in Chan’s office in tears. “Smell affects your sense of security, safety and your social life. It’s really intertwined with memory,” says Chan.

The loss of smell can come not only from chronic conditions or colds, but just as we can slowly lose our hearing as we get older, we can also slowly lose this sense, says Chan. We’ve heard more about the loss of smell since COVID-19, which attacks the olfactory system, says Chan. Countless COVID-19 patients have lost their sense of smell.

“If you don’t lose smell, you don’t really know how important it is for you. Some of my patients become truly devastated and that’s the main thing that they want back even if they can’t breathe, if they have pain or a runny nose all the time,” says Chan.

Today, when I pick up my bottle of Saroash, which has literally captured my mom in a bottle, I don’t only envision her, but I feel that sense of safety, security — and love. Scent, in other words, has the power to be so much more than what we might think. It can be a whole world of emotions. To lose our sense of smell would be to lose ourselves. •

By Jim Oldfield

Cannabis has long been linked with memory loss. From Dude, Where’s My Car? and other weed films, to the yellow warning labels on legal cannabis products and a strong body of research that shows cannabis impairs recall — the idea that pot disrupts memory is firmly lodged in the public mind.

Or it was, at least. Collective concern about the link between cannabis and memory may be fading as governments legalize recreational access to cannabis. Their aims include encouraging more responsible use, regulating the supply of cannabis products and destigmatizing historically marginalized groups.

In Canada, five years after the legalization of recreational cannabis, many experts see some progress toward those goals. But at the same time, more Canadians are using the drug, highly potent products have proliferated, and public awareness of the harms of cannabis is sketchy.

“Many Canadians see the negative effects of cannabis on memory and other aspects of health as collateral damage, if they’re aware of them at all,” says Tony George, a psychiatry professor at the Temerty Faculty of Medicine and a clinician-scientist at the Centre for Addiction and Mental Health (CAMH), who has studied substance use and addiction for decades.

Memory is an essential brain function because many other forms of cognition depend on it, says George. Memory tests are standard in most cognitive assessments, and issues with memory can signal everything from minor health problems to major neurodegeneration.

Many studies have found that cannabis affects short-term memory. In 2021, George and colleagues published a systematic review of cannabis research in the previous 30 years. It showed that in the majority of studies, cannabis use among healthy people was associated with impairments in verbal, episodic and working memory.

Another review by George’s lab found that the negative effects on memory were more pronounced in people with existing conditions, especially schizophrenia and depression. This finding dovetails with clinical studies by George’s team, which show that abstinence from cannabis in people with depression and other disorders can positively affect memory. 

These results underscore the risk cannabis poses to vulnerable people — often forgotten in public debate on legalization — and highlight long-standing inconsistencies in cannabis research. “There hasn’t been much systematic, rigorous study of cannabis,” says George. “Study populations vary, as do doses and routes of administration.”

The upshot is that some key questions on cannabis’ effect on memory are unanswered, including how long impairments to short-term memory last, and to what degree. This uncertainty could well give Canadians pause, but instead, legalization has coincided with more people using the drug.

The number of Canadians who consumed cannabis grew six per cent between 2017 and 2020, to about one in five, according to a new report from Statistics Canada. That trend had been evident for decades, but it continued across most age groups after legalization and remained highest in those aged 18 to 24, who also reported the most frequent use.

The numbers in youth aged 15 to 17 were stable, but a trend toward fewer users in that group stopped after legalization. “The government likely hoped to see fewer adolescents using cannabis, since protecting them was one goal of making it legal,” says Justin Matheson (PhD ’20), a postdoctoral fellow in the lab of Bernard Le Foll, a pharmacology and toxicology professor at Temerty Medicine and a clinician-scientist at CAMH.

Studies have raised concerns about the effect of cannabis on brain development in young people. But Matheson says the post-legalization surge in high-potency products, readily available in retail stores and embraced by young users, is also worrying. Levels of tetrahydrocannabinol (THC), the main psychoactive compound in cannabis, now average 15 per cent in dried weed — a five-fold increase from past decades.

“Potency is a huge concern,” says Matheson, who studies cannabis use and its health effects. “A lot of dried cannabis is now 30 per cent THC.

With edibles and oils, some of which reach 90 per cent THC, it’s easy to get massive doses.” The long-term effects of stronger cannabis on memory are unknown, but Matheson says acute memory impairment is clearly, if not neatly, dose related.

A Toronto woman who quit long-term cannabis use in 2021 after being treated at CAMH, says her memory was worse during periods of heavy use. “I’ve always been forgetful, but day-to-day stuff was definitely harder to remember and keep organized,” says the 27-year-old, who chose not to be identified.

For a good high, she recalls needing increasingly stronger doses of THC, sometimes every hour, but her memory of those times is hazy. “They seem like a dream. I know certain things happened, but it’s like they happened to someone else,” says the woman, who later returned to school and is now a nanny and personal support worker.

The woman was aware of some of the risks that cannabis poses to memory and health, but says she ignored them. “I was young and didn’t care. And essentially, I was often unhappy. Cannabis made me happy.”

Herein lies another challenge to Canada’s cannabis framework: how to raise public awareness and make cannabis education more effective. 

Before legalization, many Canadians held benign views on cannabis and safety. Only 58 per cent of respondents in the 2017 Canadian Cannabis Survey said that the drug had a negative effect on memory, for example. And only half of those who had used cannabis in the previous year said it affects driving ability.

Since legalization, most data show that Canadians are increasingly aware of the potential harms from cannabis, but progress has been slow. And some other signs are worrying. In the 2021 Canadian Cannabis Survey, far fewer people reported seeing warning messages on cannabis products or noticing education campaigns.

Moreover, gaps exist in the cannabis research that should complement those public health efforts. “Research has not accelerated the way we hoped it would after legalization,” says Ruth Ross, a pharmacology and toxicology professor at Temerty Medicine and the director of the Toronto Cannabis and Cannabinoid Research Consortium.

Ross says that while bureaucratic regulations have hindered research, the low funding levels for research and cannabis education are a bigger issue. Federally, the government committed $108 million for public health messaging on cannabis from 2017 to 2023. But it’s fair to ask if that’s enough, given that the gross domestic product of Canada’s cannabis sector is over $10 billion annually.

Provincially, the allocation of cannabis tax revenues has varied. The Ontario Cannabis Store put only 0.1 per cent of its $170 million in net income to a social impact fund last fiscal year, Ross noted in a recent opinion piece. In contrast, Quebec put all $95 million in net earnings toward its cannabis prevention and research fund.

Ross says that since the legalization of cannabis, emerging data suggest that cannabis-related harms are lower in Quebec than in other provinces. “We’re facing major challenges with our model of legalization, but we could still get it right, and Quebec could be a guide,” she says. “We need to be flexible.”

Canadians may not have forgotten that cannabis affects memory, but we might do well to remember what we know — and don’t know — about cannabis and its harms. •

Content warning: mentions death by suicide.

By Emma Jones

Kevin Rankin was known for always making time to support a friend in need.

“Kevin’s friends and former classmates still reach out to us, even now, to share how he helped them build a computer from scratch, or tutored them through a difficult course in high school or college,” says Kevin’s mother, Marie Rankin. “He was always so eager to help, and they still remember him for it.”

A gifted student and technology whiz, Kevin’s natural curiosity and passion for science earned him many awards and accolades throughout his school years in Trenton, Ontario. In 2017, Kevin graduated from Algonquin College’s Electrical Engineering Technology Program at the top of his class. He went on to work in the field in Toronto and Ottawa, before returning to southeastern Ontario in 2018 to take a position with a Napanee-based solar farm.

Despite previously telling his family that he was happy, in November 2018, Kevin confided to his parents that he was experiencing increasingly dark thoughts. Gord Rankin, Kevin’s father, and Marie quickly sought help. They consulted their family physician and took Kevin to their local hospital’s emergency department, where he received outpatient support from crisis counsellors. Less than two weeks later, Kevin died by suicide. He was 22 years old.

“It was devastating. He knew what he meant to us, but we could not break the pattern of his thoughts,” says Marie. “I kept asking, ‘Why could nobody help him feel better?’ Now we understand that, even though progress has been made, we still have so much to learn about treating mental illness.”

Grieving Kevin’s loss, Marie and Gord decided to take action to honour their son’s life and help other young people experiencing mental health challenges. Their goal was to recognize the spirit of a young man who gave so much to others and who had so much more to give. In 2019, they endowed the Kevin Gordon Rankin Memorial Award in support of clinical trainees in the Temerty Faculty of Medicine’s Department of Psychiatry. The award recognizes trainees who demonstrate a particular interest in, and aptitude for, working with young adults with severe mental illness.

“We wanted to do something so Kevin’s memory lives on long after we are gone — so something good can come out of what happened,” says Gord.

David Carlone (PGME ’23) is the award’s most recent recipient. Carlone received the award because of his commitment to improving the lives of young people struggling with mental illness. Having completed his training, he is now a faculty member in Temerty Medicine’s Department of Psychiatry and a staff psychiatrist at The Hospital for Sick Children, where he cares for children and youth experiencing depression and other forms of mental illness. Carlone says knowing Kevin’s story has added meaning to the work he does every day.

“This award is a poignant reminder of the urgency and importance of addressing mental health issues, especially among young people,” says Carlone. “It’s particularly significant because it honours the memory of someone who experienced significant mental health challenges.”

Carlone is dedicated to promoting mental wellness among young people through his clinical work and patient advocacy.

“My focus is on providing compassionate care and advancing new forms of evidence-based treatment,” says Carlone. “I’m optimistic and hopeful for the future of child and youth psychiatry.”

Today, Marie and Gord continue to share Kevin’s story with others (including their two-year-old son, Travis) and provide peer support to families experiencing mental health challenges or who have lost a child. The family also looks forward to meeting with the recipients of Kevin’s namesake award — finding comfort in the trainees it supports, and their contributions to child and youth psychiatry.

“It’s encouraging to see the different areas the recipients are working in,” says Marie.

“It gives us hope to learn about the new ways mental illness is being treated.” •

A Strange Juxtaposition

The beginning of the pandemic has become this weird, hazy time in our minds. At the time, though, it was so visceral. It dominated our thoughts at every moment.

At the Toronto High Containment Facility where we have the largest containment Level 3 lab in Ontario, we would never compare our pandemic experience to that of our clinical colleagues. We weren’t on the front lines dealing with patients, and watching the overall stress on the health care system. But, we were putting our all into running the lab and making sure it was working as efficiently as possible to learn everything we could about the new virus.

I’m a virologist by training. This is what I have wanted to be since I was 15 years old. I’ve always been fascinated by viruses. A virus is a tiny microbe that doesn’t even really classify as a life form. It needs to get into another cell to replicate itself. And yet, it has the potential to obliterate a person and put society at a standstill.

In March 2020, I stood behind a microscope with the first culture of the SARS-CoV-2 virus in Canada. With our work in the lab investigating COVID-19, I had a feeling of scientific curiosity. But, at the same time, I also felt devastated by what I knew was happening outside and the potential of what could happen. It was a strange juxtaposition of feelings.

Now, we’re using what we learned from the pandemic to investigate future health threats, such as antimicrobial resistance. Our memories of 2020 will help us figure out what to do better the next time a pandemic happens. We have a lot of the tools. In the future, it will be a question of how we use them.

Natasha Christie-Holmes (PhD ’08) is the director, strategy & partnerships at the Emerging and Pandemic Infections Consortium at the University of Toronto.

The Brain is for Moving

My work as a geriatrician is motivated by love. In my family, people live long. My grandmother, from Haiti, lived to be 98 years old, and with diabetes. My other grandmother lived to 92 years old, and my grandfather to 89 years old. My father is a psychiatrist. I have a minor in psychology. I’ve always been interested in things that have to do with the brain. 

Part of my role as a geriatrician is helping older patients with dementia improve the quality of their lives. I’m especially interested in seeing the rise of non-drug approaches to help patients. Dementia is a complex condition. I support a multi-pronged approach.

For example, one thing that can help people with dementia is exercise and music. I was a physical therapist before I was a physician. That’s why I tell people the brain is not just for thinking, it’s for moving. For people with dementia, a walk outside, if they’re able, can help them considerably. 

Another area I’m really passionate about is how we can do a better job of helping caregivers of people with dementia. I see caregivers bringing in their loved ones in such distress, and mourning the loss of the person they love. People who have dementia may show signs of apathy and can be difficult to engage. They can withdraw from other people. But part of our survival as humans depends on communication with other human beings. 

Mireille Norris (PGME ’00, MHSc ’01) is an assistant professor at the Temerty Faculty of Medicine’s Department of Medicine and a staff internist geriatrician at Sunnybrook Health Sciences Centre.

The Molecular Mystery

There is still so much that is unknown about how the human brain stores memories at a molecular level. For example, take a song that you hear when you are a teenager, then don’t hear again for 40 years. One day, it comes on, and you immediately recognize it. How did that memory get stored and maintained for four decades?

For me, answering that kind of question is my goal. In the past, to help understand how memory works, I’ve done research looking at mice and worms. We’ve studied what changes take place on a cellular and molecular level as memories are formed. Our hope is that we’ll be able to learn more about the human brain and human nervous system by looking at how worms and mice form memories.

What we’ve learned so far is intriguing. 

For example, we were able to show that the tiny C. elegans worm could form and retrieve short-term memories. In our experiment, worms normally liked the smell of almonds and moved toward a chemical with that scent. However, when the worms’ food was removed and the scent was present, they started showing an aversion to the smell and began moving away from it.

We figured out that the memory was stored in a single neuron in the worm’s nervous system, and that helped us pinpoint the exact molecules that store the memory. 

It’s this type of work that we hope will explain how people can store information for long periods of time. Humans definitely have brains and nervous systems that are much more complex than those of mice or worms. Part of the most interesting part of our work is going back and forth between species, and seeing what translates, and what doesn’t. 

Derek van der Kooy (PhD ’80) is a professor in Temerty Medicine’s Department of Molecular Genetics and the Donnelly Centre for Cellular and Biomolecular Research.

The Bilingual Mind

A lot of my work is with people who are bilingual, or multi-lingual. 

Using two languages puts a lot of cognitive constraints on the human mind. It can look very fast and easy, but there’s actually a lot of mental work that goes into using the right one in the right context. Selecting the right language is a big cognitive task. 

Something my research has shown is that bilingual people learn to associate specific people to the specific language they should use with them. By forming these type of memories, it can lighten the cognitive load. Memory is a basic requirement for language development. 

Right now, about 40 per cent of Canadians speak more than one language, a number that has risen with time. Even though there are so many people who are bilingual, we still do not have very clear theories on the brain’s architecture when it comes to bilingualism. 

We still have so much to learn about the way people organize different languages in their mind. We’re not walking around with two boxes in our brain, where we open one box  to use one language, and open another box to use a second language.  

The bilingual mind is not simplistic. It’s more context-dependent than that. We need more research that focuses bilingual people, and to develop theories, tools and assessments that are appropriate for them. 

Monika Molnar is an assistant professor at Temerty Faculty of Medicine’s Department of Speech-Language Pathology and Rehabilitation Sciences Institute. 

Strength,
Stoicism
and Stigma

By Heather McCall

Sometimes, important work comes about in an unanticipated way. At least that’s been the experience of psychiatrist Janet Ellis (PGME ’11), who never expected to be exploring military veterans’ mental health in a first-of-its-kind role in Canada.  

Twelve years ago, as a new staff psychiatrist at Sunnybrook Health Sciences Centre, Ellis started seeing patients from the hospital’s Tory Trauma Program — the oldest and busiest trauma centre in Canada.       

“I was seeing people who weren’t able to leave home after a car accident because they couldn’t handle the sound of traffic, or because an ambulance siren would trigger flashbacks and nightmares for them,” she says. The experience propelled Ellis into a new area of study, about how people manage trauma, instead of her previous focus on psychosocial oncology. 

After six months of attending Sunnybrook’s trauma ward rounds, she began treating more patients with post-traumatic stress disorder (PTSD). Those patients included public safety personnel, such as firefighters, paramedics and police officers. Ellis noticed their behaviour was different than those who had experienced acute trauma from a single incident. For public safety personnel, PTSD was often deep-seated and insidious, and the result of regular exposure to traumatic scenes over time. Ellis determined that, more often than not, the patients’ PTSD symptoms would be largely ignored until they became unmanageable.

“Unfortunately, this is the worst-case scenario for someone with PTSD,” she says. “The longer you avoid treatment, the more difficult it becomes to treat. It’s a vicious cycle.”

In 2022, Ellis learned about a new opportunity in which she believed she could use her expertise in treating PTSD in a new way: as the inaugural Professor of Veteran Mental Health, a donor-funded professorship in the Temerty Faculty of Medicine’s Department of Psychiatry. As Ellis explains, members of the Canadian Armed Forces often have repeat exposure to traumatic events but may avoid care due to the stigma of being seen as weak within the military culture and the fear of not being able to serve on missions.

“Historically, military culture has been characterized by strength and stoicism,” says Ellis. “It can feel stigmatizing for a current or former member of the Armed Forces to acknowledge their difficulty in coping with the stresses of their work.”

These challenges are compounded by other unique barriers that members of the military face, she adds. For example, a military member’s eligibility to serve can be affected by a requirement for a prescription drug, such as those used to treat anxiety or depression. Ellis also notes that even when veterans with PTSD do seek out support, some may struggle to navigate access to specialized supports. Or, they may encounter barriers with civilian health care providers. These providers may have little understanding of the military’s unique culture, says Ellis, so they may be ill-equipped to assess or deliver the specialized care that veterans need.

Through the professorship, Ellis is seeking to identify who is most at risk of encountering barriers to health care, and how to ensure they don’t fall through the cracks. That’s why a major focus of Ellis’ current work is collaborating with various organizations to make it easier for veterans to seek the help they need from public and military service providers, and to improve system responses.

One example is the Toronto Police Service, which launched the Military Veterans Wellness Program in 2022 to educate and train police officers to respond better to veterans in crisis. Peter Collins (PGME ’89), an associate professor of forensic psychiatry at Temerty Medicine as well as a Canadian Armed Forces veteran who served in Afghanistan, introduced Ellis to the program. Ellis hopes to study the program’s impact and any learnings that can be translated to the broader health care system. Ultimately, the greatest impact Ellis says she can have in her new role is to lead much-needed changes to veteran access to effective health care, in all spheres.

“That work means identifying veterans in health care settings, understanding their experience and culture, and acknowledging their specific health requirements,” she says. “The Canadian health care system has a long way to go when it comes to addressing veterans’ needs, and that work is crucial.” •