Stress can kill. Recent studies have shown the far recesses of our mind can have a profound impact on our physical health. Severe depression has been linked to a variety of health problems: everything from heart disease, to stroke, back pain, multiple sclerosis, and possibly type-2 diabetes. It’s a dangerous world, especially when we’re not even safe from our own minds.

Dr. Turhan Canli, currently a psychology professor at Stony Brook University, has been exploring the implications of some of these dangers. By looking at different personality factors, Dr. Canli and his team are unpacking the mysterious link between mental health and physical health. With a special focus on loneliness and purpose in life, his studies try to pinpoint connections between mental states and overall well-being.

In a recent interview with Ivy Magazine, Dr. Canli discussed this research and outlined some of the fascinating discoveries he’s been working toward. Read more about his findings and be sure to connect!

Dr. Turhan Canli is an IVY Member (NYC). Connect and collaborate with him here.

IVY: How would you describe your research to a non-science person?

I’m researching what makes each of us unique at a biological level. So, I look at peoples’ brains and genes but also at their various life experiences and how all of these things become intertwined. Everything’s happening somewhere in the brain, and my work helps us understand how individual differences and personality form.

IVY: What’s the most surprising thing you’ve found to date?

We’ve been looking in particular at loneliness. Loneliness is a really fascinating social experience because it is independent of the size of your social network. It is a subjective experience. You can have a large social network and feel lonely, or have no social network and not feel lonely at all.

Loneliness is also a psychological mindset with profound physical effects. People who are lonely are more likely to have all kinds of illnesses, including cancer, inflammatory diseases, and heart disease. How is that possible? How does that work? It’s the mind-brain connection. Something about the subjective state of mind can have a profound influence on your wellbeing. That link is surprising and extremely compelling.

Recently, we’ve been looking at brain regions of individuals who are now deceased. When the patients were alive, they collaborated with researchers so their psychological state could be analyzed. Now, we have access to the patients’ brain tissue, which enables us look at genes that are expressed differently as a function of loneliness. Gene expressions are important because they are basically a translation from the mind to the brain. We’ve found there are genes that are more or less expressed as a function of people’s level of loneliness. These genes have profound effects.

IVY: What’s your next big research project?

My next big project is going to be around “purpose in life,” or the feeling of having direction and meaning.

Colleagues of mine have done longitudinal studies on aging populations in their sixties, seventies, and eighties, tracking mental and physical health. What they discovered was that individuals who have a high level of purpose in life tend to age a lot better. They get less sick, they have fewer kinds of health problems, and they’re 20% less likely to develop Alzheimer’s disease. And even when they do, they appear to be much better off than they really are. When they show up to an interview with a clinician, they seem a lot more cognitively intact than they actually might be. This is a function of purpose in life. There is something to be said about real physical and mental health benefits to having a high purpose.

How does that work? We’ve done some research that looks at stress hormones and how people look at stressful situations. The research is in its very early stages, but one way to think about high purpose in life is that “purpose” may be a psychological buffer against stress. People with more purpose in life seem to have healthier stress reaction than those with less purpose.

IVY: You have theorized that depression might be an infectious disease. What is that theory based on, and how would you prove it?

There is no one form of depression, but some kinds of depression are known to produce brain changes—so it may change the neurotransmitter regulations, or the volume and size of specific regions in your brain. Nobody knows why that is. The medications that we’re using today are mostly designed to rebalance neurotransmitters. That’s an approach that has not changed in sixty years, and it doesn’t work well for depression. We need to think about a different approach.

Why does no one know the mechanisms for those brain changes? One explanation for the change in your brain could be due to pathogenic infection—so a virus, bacterium, or parasite. Some parasites have proven ability to change the brain physiology of organisms they infect, and those changes are similar to a depressed patient. But no one has done a large-scale, rigorous study to investigate these similarities. We need to do that, not only to look for parasites we already know about, but also to use cutting edge molecular tools to discover new ones that we don’t know about yet. If I’m right, we’ll probably discover a whole family of different pathogens that can alter human brain physiology, explaining depression and other mental illnesses.

To get the ball rolling on this hypothesis, we designed a probe that can detect 180,000 different molecules from various bacteria, viruses, and pathogens, and we plan to run a small pilot study on depressed patients to see if we can gather enough new data for a large-scale funded project.

IVY: How can the IVY Community help support you?

If anyone is working with a Foundation that’s interested in psychiatry-related research or supporting causes that have to do with mental health, that’s always a good connection to have. Let’s talk! I can’t do anything unless I have funding to make it happen.