How physical exercise acts as an antidepressant

In conversation with Garcia Ashdown-Franks on the effects of exercise on depression

How physical exercise acts as an antidepressant

Exercising regularly could function effectively as an antidepressant, according to a recent review paper co-authored by U of T researchers.

One of the researchers, Garcia Ashdown-Franks, a PhD student in exercise science, spoke with The Varsity on how the psychosocial mechanisms of exercise could cause antidepressant effects.

The impact of exercise on self-esteem

Self-esteem is the extent to which one’s conception of themself is positive. According to multiple studies over the past decade, sustained low self-esteem is a predictor of depression.

Symptoms of depression, according to the American Psychiatric Association, include a loss of interest in activities one once enjoyed, mood shifts to sadness, increased fatigue, and feelings of worthlessness. These are indicators of depression when experienced for two weeks or longer.

Low self-esteem may result in depressive symptoms, which could further erode self-esteem. According to the co-authors, this creates a cyclical relationship between the two.

Poor self-perception of one’s physical body is one factor that can impact self-esteem, and thus create depressive symptoms. According to the review, exercise can break the cycle by boosting physical self-perception, and thus self-esteem.

Increase in muscle mass and fat loss are two possible mechanisms that could drive the effect, according to the review. However, according to The New York Times, fat acceptance advocates and academics promote feeling self-confident at any weight. Learning to feel comfortable with one’s body weight may be another pathway to increasing self-esteem, aside from exercise.

Interestingly, two studies in the review also suggest that even if body composition remains the same, exercise may still increase self-esteem.

Ashdown-Franks noted, “Just the act of performing exercise or activity or sport can make us feel better about our body, even if there are no actual changes in our body composition.”

How exercise can change your social life

“There’s evidence that people with depression report feeling less social support in their lives, or [fewer] people [who] they can go to for support, which also can [worsen] their symptoms,” Ashdown-Franks said to The Varsity.

The co-authors noted that physical engagement is associated with emotional support from friends and family, and further suggested that the social benefits of exercise could be pronounced in team sports.

Ashdown-Franks said that the evidence is limited regarding whether solitary sports — such as running and weightlifting — could also result in social support. However, she noted that interaction with others, such as fellow runners or coaches, could provide a sense of community.

Team sport activities are prevalent at U of T. For example, there are drop-in basketball sessions at UTSG, UTSC, and UTM. Drop-in tennis, volleyball, and yoga are alternative options on campus.

Social impacts underpinned by biological mechanisms

Long-term exercise also induces biological changes, which could play a role in the antidepressant effects of exercise as well.

According to the co-authors, these biological mechanisms include changes to structures in the brain. The findings of animal studies report that the growth of neurons in the hippocampus, an area of the brain relevant to depression, can be stunted by the condition.

Exercise may be a long-term way to improve the growth of neurons, with studies finding that exercise can specifically increase the volume of the hippocampus. Further factors that boost neural growth include increased blood flow to the brain.

Inflammation in the body is another possible cause of depression. Evidence shows that exercise can lower the levels of pro-inflammatory markers associated with depression, as exercise may be responsible for the release of anti-inflammatory biochemicals.

Future steps of research

“I think there’s a lot more research that needs to be done,” said Ashdown-Franks, regarding research on the relationship between exercise and depression.

Understudied research areas, according to Ashdown-Franks, include determining the optimal exercise routine for combating depression. Other limitations of studies on overcoming depression include their reliance on self-reports, which have limited power, and on animal studies, which may not be applicable to humans.

Despite a lack of clarity of the research, Ashdown-Franks emphasized that it’s clear that some exercise is better than none at all. She said, “For someone who’s struggling with depression or symptoms of depression, they might think going to the gym [can be] a monumental task. But… [taking] a few minutes every day just to go for a walk [can make you] feel better.”

How psychotherapy treats depression differently than antidepressants

A personal exploration into the science behind antidepressants and CBT

How psychotherapy treats depression differently than antidepressants

Content warning: discussions of depression and suicidal ideation.

The first time I walked through the door of my psychiatrist’s office, I was full of doubt. I had been feeling low for quite a while, and I had trouble believing that any treatment would truly help me feel better.

I had just completed my second year of university, and I felt broken and exhausted. A blend of burning out, experiencing depressive episodes, disengaging from pastimes I used to enjoy, and fantasizing about dying drove me to seek treatment at U of T’s Health & Wellness Centre.

As part of my initial assessment, which occurred over the course of several sessions, my psychiatrist asked me questions about practically every aspect of my life: recent events, medical history, sleep patterns, appetite, suicidal ideations, and more. After considering all my symptoms, she prescribed me Prozac, an antidepressant medication, and recommended cognitive behavioural therapy (CBT). Both are common treatments for depression.

I gave them both a try. I was fortunate to be able to see a therapist for CBT, which was covered by my family’s health insurance. At first, I was skeptical that it would work, but I decided to commit myself to at least a few sessions.

CBT, as I learned, is a short-term form of psychotherapy that helps people build skills for staying healthy. In essence, it helps people identify, question, and change distorted thoughts and beliefs they might have about themselves and the world. By recording their thoughts during upsetting situations, people examine how their unhelpful thoughts might contribute to problems like depression.

Research on how CBT compares to antidepressants

Dr. Zindel Segal, a U of T psychology professor and an expert in CBT, said in an interview with me that “when people are in certain mood states, they tend to have thoughts that are very compatible with those mood states. So, when someone’s feeling depressed, they’re more likely to feel hopeless, judge themselves, and be very critical.”

According to Segal, CBT provides a way of treating people’s thoughts and assumptions as hypotheses that can be tested, rather than as hard facts. “That can help people alleviate the impact that some of these thinking styles can have on their moods,” he elaborated.

For me, CBT was extremely challenging more so than any math or biochemistry course I have ever taken. Perceptions are simply hard to change. At the time, for example, I felt incredibly worthless and undeserving of love. In the face of this, CBT helped me stay objective and not always accept my perceptions as truth. Psychotherapy made me stand back from my thinking to consider situations from different viewpoints.

“In the face of [critical challenges], CBT helped me stay objective and not always take my perceptions as truth.”

However, distorted thoughts and beliefs are often not the only culprits of depression. Much is still unknown about the causes of depression, but researchers suspect that chemical imbalances in the brain play a role in maintaining low moods. Antidepressant medications are designed to address these chemical imbalances by boosting concentrations of neurotransmitters namely serotonin and norepinephrine in the brain.

At first, I was very reluctant to try antidepressant medication because I was wary of possible side-effects. However, my psychiatrist assured me that the starting dose was low, that I would be closely monitored, and that we could always adjust my treatment if the medication was not right for me. In the end, I experienced only minor side-effects and really benefited from the resulting stability in my mood.

The differences between CBT and antidepressants

So, what are the differences between CBT and antidepressants in treating depression, according to experts? Researchers like Segal, who recently co-authored a paper comparing the efficacy of CBT versus antidepressants, are working hard to answer this question.

Segal’s research team found that CBT and antidepressants target different symptoms of depression. Antidepressants were found to be best for treating symptoms specifically related to depressed mood, feelings of guilt, suicidal thoughts, and psychic anxiety.

On the contrary, CBT and antidepressants were equally effective in treating patients who struggled with other specific symptoms of depression, like changes in sleep and appetite. “This paper tries to address more of a symptom-to-patient matching approach so that people are getting antidepressants if they have a symptom profile that might be more responsive to the drug,” said Segal.

In my case, CBT and antidepressants were temporary treatments that helped me bounce back from a bout of depression and develop long-term skills in staying healthy. Each treatment helped me in different ways: CBT helped me build emotional resilience, whereas antidepressant medication gave me the extra energy to ‘get back on my feet’ and return to doing the things I love to do.

But whichever treatment people are prescribed, Segal stressed that depression is treatable. “Whether you have hypertension or depression, it is possible to get treatment.”

If you or someone you know is in distress, you can call:

  • Canada Suicide Prevention Service phone available 24/7 at 1-833-456-4566
  • Good 2 Talk Student Helpline at 1-866-925-5454
  • Ontario Mental Health Helpline at 1-866-531-2600
  • Gerstein Centre Crisis Line at 416-929-5200
  • U of T Health & Wellness Centre at 416-978-8030.

Warning signs of suicide include:

  • Talking about wanting to die
  • Looking for a way to kill oneself
  • Talking about feeling hopeless or having no purpose
  • Talking about feeling trapped or being in unbearable pain
  • Talking about being a burden to others
  • Increasing use of alcohol or drugs
  • Acting anxious, agitated, or recklessly
  • Sleeping too little or too much
  • Withdrawing or feeling isolated
  • Showing rage or talking about seeking revenge
  • Displaying extreme mood swings

The more of these signs a person shows, the greater the risk. If you suspect someone you know may be contemplating suicide, you should talk to them, according to the Canadian Association for Suicide Prevention.