Dana Yates

Understanding the depressed mind: how the brains of new mothers may hold the keys to treatment

sgupta — Fri, 15 Aug 2014 11:38:12 +0000

Understanding the depressed mind: how the brains of new mothers may hold the keys to treatment sgupta Fri, 08/15/2014 - 07:38

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Dr. Jeffrey Meyer uses brain imaging technology to detect elevated levels of chemicals in the brains of those with depression (photo by Christopher Wahl)

Dana Yates

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Dana Yates

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Breaking Research

Features

Medicine

Hospital

CAMH

Brain

Research

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Dr. Jeffrey Meyer on what we can learn from postpartum depression

The death of award-winning actor and comedian Robin Williams has put depression and mental health issues back in the headlines.

Scientist Jeffrey Meyer of the ��Ƶ and CAMH conducts research into depression and the brain. In this profile from Edge, a publication of U of T's Office of the Vice-President, Research and Innovation, Meyer discusses his research into the role of an enzyme called MAO-A and his work to devise interventions that would help prevent depression in anyone from new mothers to the general population.

Depression is a disorder of many names. Winston Churchill, for example, called his depressive episodes the “black dog.” Others, meanwhile, refer to the condition as the blues or the blahs. Despite the colloquialisms for depression, the reality is the disease can feel like a dark, endless tunnel — one that researcher Jeffrey Meyer hopes to prevent people from entering.

Meyer, an MD/PhD and professor in the ��Ƶ’s departments of Psychiatry, and Pharmacology and Toxicology, is head of neurochemical imaging for the Mood and Anxiety Disorders program at the Centre for Addiction and Mental Health (CAMH). Also the Canada Research Chair in Neurochemistry of Major Depressive Disorder, Meyer is focused on answering one question: what is needed to have a healthy brain?

To that end, Meyer wants to create specific recommendations to help people sidestep major depressive disorder. Typically just called depression, the condition is much more than a brief period of melancholy — it involves ongoing feelings of deep despair.

“Ultimately, we would like to say, ‘Here are four things you should do to avoid depression',” Meyer said. “It would be similar to the strategies for avoiding heart disease, which include eating right and exercising, but in the case of depression, the strategies would be more complicated than simply saying ‘avoid stress'.”

That advice could have a significant impact on mental health worldwide. Indeed, depression affects more than 350 million people globally, according to the World Health Organization. While there are treatments for the condition, such as medicine, therapy and lifestyle changes, they don’t seem to work for everyone. And at its worst, depression can lead to suicide. In fact, one million people take their own lives each year around the world.

So what happens in depressed brains? Meyer is focused on monoamine oxidase A (MAO-A), an enzyme that breaks down the chemical messengers serotonin, dopamine and norepinephrine. When the brain is depleted of those mood-related substances, people experience a sad emotional state. And those feelings, along with pessimism, are harbingers of depression.

Although scientists long believed that a chemical imbalance in the brain caused depression, in 2006 Meyer and his colleagues determined conclusively how that process actually works. Using a brain imaging technique called positron emission tomography, the researchers found that the level of MAO-A was considerably higher in the brains of those with untreated depression. Meyer subsequently made other landmark discoveries. For instance, he found that MAO-A is elevated in several high-risk states for clinical depression, including prior to the condition’s recurrence, during early withdrawal from heavy cigarette smoking and just after childbirth.

Today, Meyer is using that information to study and assist those with high MAO-A. For example, he has developed a natural health product to help regulate the MAO-A of new mothers with postpartum depression. After giving birth, a woman’s estrogen level drops considerably, triggering a surge in MAO-A level.

"We have developed a measure of postpartum blues that can be used to screen combinations of ingredients in the supplement," said Meyer. "Postpartum blues is the healthy range sadness that tends to peak on day five postpartum and when severe is associated with later clinical level postpartum depression.

"If we reduce postpartum blues we hope to reduce risk of postpartum depression. We are now piloting the supplement to see to what extent it reduces severity of postpartum blues."

It would still be a few years before the product might reach the market. Meyer is now testing the dietary supplement on new mothers in an open trial (where all patients receive the supplement) and the next step would be to test the product in a randomized, double-blind trial.

Meyer also aims to develop interventions to adjust the MAO-A of people at increased risk of depressive symptoms, including premenopausal women and those with substance addiction. As well, on top of designing preventive strategies to help the general population avoid depression, Meyer hopes to bring peace of mind to those with the treatment-resistant form of the disorder. That two-step process will involve identifying subtypes of depression and determining which treatments best normalize brain changes in each subtype.

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How walkable is your city?

sgupta — Mon, 09 Dec 2013 16:04:22 +0000

How walkable is your city? sgupta Mon, 12/09/2013 - 11:04

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Professor Paul Hess studies the walkability of neighbourhoods as well as access to public transit and cars (photo by John Hryniuk)

Dana Yates

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Dana Yates

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Paul Hess: don't ignore pedestrians in urban planning

When most people think about urban transportation systems, they focus on infrastructure, including streets, subways and even sidewalks. ��Ƶ researcher Paul Hess takes a much broader perspective.

“Transportation touches many issues,” says the geography and planning professor. “It affects our quality of life. It affects energy use and the environment. And it affects social equity – that is, who has access to transportation and who doesn’t?”

To that end, Hess studies how cities are designed and built to accommodate people’s transportation needs. In particular, he is interested in neighbourhoods’ suitability for walking as well as residents’ access to cars and public transit. For instance, in one current project he is studying how immigrants who don’t have driver’s licenses or can’t afford a car get by in the “car-dependent” outer suburbs of Brampton, Mississauga and Markham.

In another initiative, Hess is collaborating with the provincial transportation agency Metrolinx to investigate walkability in areas surrounding transit stations. Specifically, he is looking at whether pedestrians have access to safe, direct routes to public transportation hubs.

Ease of walking in the urban environment has grown in importance during the last 20 years, says Hess. “At one point, you never heard the term ‘walkability,’ but now real estate listings feature ‘walk scores.’ That’s because walkable places are considered good places to live.”

The problem, he continues, is that walkability now divides neighbourhoods. It may be highly valued within higher-income areas of the inner downtown, but in lower-income communities of the inner suburbs – such as those in Scarborough and north Etobicoke – walking is less a lifestyle choice and more a matter of necessity, since residents have no or limited access to cars. Within these neighbourhoods, however, there are few pedestrian-friendly zones – and changing social patterns may be responsible for the situation.

Originally, inner-suburban neighbourhoods were built around schools and single, detached homes. But with more families living in sprawling, high-rise apartment buildings, children are forced to walk long distances and to cross large, busy roads in order to get to school. Hess is working to raise awareness of these challenges in marginalized communities.

“If we can get engineers, planners and pedestrian advocates to work together better, then we’ll shift from the old outcome of getting cars around to a new outcome of increased walkability,” he says.

Dana Yates is a writer with the U of T magazine Edge, where this article originally appeared. Read more stories in Edge.

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Using computer models to help our fragile ecosystem

sgupta — Mon, 24 Sep 2012 10:09:03 +0000

Using computer models to help our fragile ecosystem sgupta Mon, 09/24/2012 - 06:09

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Assistant Professor Benjamin Gilbert studies biodiversity and environmental adaptation (photo by John Hryniuk)

Dana Yates

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Dana Yates

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Faculty of Arts & Science

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From the northern boreal regions to the southern tropics

Global warming is well-known for its effect on the climate. But it also poses a threat to the world’s ecosystems. ��Ƶ researcher Benjamin Gilbert wants to know more about that process.

Gilbert, an assistant professor in the Department of Ecology and Evolutionary Biology, examines the factors that enable species to co-exist in certain regions. “This has great importance in the context of climate change, acid rain and the arrival of invasive species,” he says. “We’re trying to get a handle on how things work and what is happening.”

To understand biodiversity, however, one must go to diverse areas. That’s because the mechanisms that drive one ecosystem can either be one-of-a-kind or can offer important lessons about other ecological communities. So Gilbert has travelled from northern boreal regions to the southern tropics, studying organisms as varied as tree seedlings and mosquito larvae. He has looked at environmental adaptation, the interaction of species and the spatial processes that promote or reduce diversity.

Studying complex ecosystems, though, requires sophisticated data management and processing technologies. And for that reason, computing plays a critical role in Gilbert’s research. In fact, without the aid of statistical models, he could very well spend all his time sorting data.

For example, in an ongoing project involving Jonathan Levine of the University of California, Santa Barbara, Gilbert is quantifying the effect of invasive grasses on native annual plants. Following a biological invasion, native species often experience reduced numbers and are forced to take refuge in small, sub-optimal areas. Using models and simulations, the researchers are generating estimates about whether these environmental changes will eventually lead to the extinction of native flora and, if so, how long it may take.

In some research projects, Gilbert is then able to compare the computer’s forecasts to actual data as a means of determining if the models are accurate. But that’s not always possible, especially when the simulations suggest that a species will become extinct in 600 to 800 years.

“Without any way to test or verify that information in the short term, you have to take it with a grain of salt,” Gilbert says. “But it does provide insight into what species we should be keeping an eye on, and gives us a testable hypothesis for the future.”

Is there hope for native species? Gilbert believes so. To that end, he would like his work to lead to more careful monitoring of species at risk of extinction. And, as a result of the increased scrutiny, governments may be prompted to take action. That could mean applying herbicides to invasive species or creating tree corridors to connect the fragmented, vulnerable forests that are left behind by fires, logging and agriculture.

“There are many ideas about how we can protect native species by reducing invaders or supporting fragile ecosystems. But without computer models, we have no way of predicting how well these interventions should work. We are beginning to use these models to make testable predictions — this will allow us to better apply the scientific method to conservation.”

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