From the Editor

It’s one of the most common and disabling illnesses. But how to treat depression in the long term?

In the first selection, we consider a paper just published by The American Journal of Psychiatry. In it, LaSalle University’s Felipe B. Schuch and his co-authors present a meta-analysis on exercise and depression. Drawing on 49 studies, they find that physical activity can protect against the development of depression, regardless of age and geographical region.

treat-alternative-exercise_an_alternative_adhd_treatment-article-3280a-man_running_sunset-ts_451886305-3Exercise: good for the heart, the lungs, and the prevention of depression?

In the second selection, Harvard University’s Roy H. Perlis writes a commentary for The American Journal of Psychiatry responding to a recent New York Times article that questioned the long-term use of antidepressants. He writes: “The informative analogy might be treatment of type 2 diabetes. While diet and exercise have a substantial impact on disease course (notably, results far more compelling than those in depression), it is hard to envision front-page articles in the New York Times about the dangers of long-term diabetes treatment.”



Exercise and Depression

“Physical Activity and Incident Depression: A Meta-Analysis of Prospective Cohort Studies”

Felipe B. Schuch, Davy Vancampfort, Joseph Firth, Simon Rosenbaum, Phillip B. Ward, Edson S. Silva, Mats Hallgren, Antonio Ponce De Leon, Andrea L. Dunn, Andrea C. Deslandes, Marcelo P. Fleck, Andre F. Carvalho, Brendon Stubbs

The American Journal of Psychiatry, 25 April 2018 Online First

Depressive disorders are the second leading cause of global burden of illness and account for more than 44 million years lived with disability. They are associated with heightened medical comorbidity, increased health care costs, and premature mortality. Given the breadth of depressive disorders and the individual and societal burden, strategies that may reduce the onset of depression are urgently needed.

One potentially modifiable risk factor for the onset of depression is low physical activity levels. People with major depressive disorder are known to have a 50% odds of not meeting the recommended physical activity levels (e.g., performing >150 minutes of moderate-intensity physical activity each week) compared with people without major depression. Moreover, structured physical activity is known to reduce depressive symptoms in those with depression. Systematic reviews have suggested that physical activity is a protective factor for depression onset, with even small amounts of physical activity (e.g., walking <150 minutes per week) decreasing the incidence of future depressive episodes. These studies, however, have not conducted meta-analyses to quantify the magnitude of the protective role of physical activity. Moreover, the role of moderators such as age and sex, which may influence the relationship between physical activity and depression, have not been explored.

Given these gaps, our aims were to systematically review and meta-analyze prospective cohort studies examining the role of physical activity in reducing the risk of incident depression; to explore potential moderators, including age at baseline, geographical location, sex, length of follow-up, study quality, number of covariates used in the model, study sample size, and total person-years; and to evaluate the quality of the studies.

dxfgt_2vwaazgsgFelipe B. Schuch

So begins a new paper by Schuch et al.

Here’s what they did:

  • The authors searched several databases (including PubMed, Embase, PsycINFO) to Oct. 18, 2017. “Searches were adapted for each database, using keywords that included a combination of terms related to physical activity, depression, and longitudinal studies.”
  • Inclusion criteria included that physical activity was measured with a self-report questionnaire (e.g., the International Physical Activity Questionnaire) and that the papers used incident depression as their primary outcome.
  • Exclusion criteria included studies without primary data.
  • “The primary outcome measure was the adjusted odds ratio (and 95% confidence interval) for incident diagnosed depression or depressive symptoms.”
  • Data was extracted including geographical location, number of participants, age, physical activity assessment, depression assessment, and the follow-up period.
  • Statistical analyses were done. “A random-effects meta-analysis was conducted investigating the relationship between baseline physical activity level and incident depression.” They also did several sub-group analyzes including for geography and age.

Here’s what they found:

  • 49 unique studies were included in the review (after an initial search yielded more than 13,000 results).
  • “Across the 49 unique prospective studies, 266,939 individuals were included, with nearly equal sex distribution (47% males), followed up for an average of 7.4 years. The total person-years was 1,837,794.”
  • “People with higher physical activity levels were at reduced odds of incident depression when compared with people with lower physical activity levels in adjusted (adjusted odds ratio=0.83…)” See figure below.
  • Re: geography. “Significant protective associations of physical activity on incident depression were found across the four continents (Asia, Europe, North America, and Oceania) with available data for adjusted odds ratio and relative risk analyses.” Re: age. “Protective effects were found for adults and older persons in all analyses and for children in adjusted odds ratio and relative risk analyses.”
  • “None of the investigated moderators significantly explained the variance of the effects of physical activity on depression onset in any of the analyses.”


To our knowledge, this is the first study to meta-analyze the relationship between physical activity levels and incident depression. Study findings indicate that across 49 studies, higher physical activity levels are associated with a decreased odds of developing future depression. The results remained robust after adjustment for potential publication bias. Moreover, our results indicate that higher levels of physical activity offer a protective effect on future development of depression for people of all ages (youths, working-age adults, elderly persons), and this finding is robust across geographical regions around the world.


A few thoughts:

  1. This is a good study.
  1. This meta-analysis tapped many studies – 49 in all. Wow.
  1. What are the limitations? The study authors note several, including that physical activity was determined by self-report measures.
  1. The paper has received much attention, including from the CBC. Dr. David Goldbloom of CAMH made the following comment to them: “This is not a Speedy Muffler guarantee against depression, rather it’s a way of lowering the risk of depression.” He adds: “We live in an age where between limitless streaming of TV, the paralytic effect of social media on human movement and the erosion of physical education … [we are] creating a more static human population. Particularly when it comes to physical activity in high schools, this is the population that’s really at high risk of developing their first episode of depression, so inculcating exercise into the culture of adolescence to a greater extent could have important mental health spinoffs.” You can find the full article here:
  2. Dr. Goldbloom mentions the HUNT study. That American Journal of Psychiatry paper concluded that 12% of future cases of depression could have been prevented with an hour of exercise a week. You can find it here:
  3. Clinical take-away message? Exercise can be useful in the prevention of depression. We can dispute aspects of this study, but it’s difficult to argue that exercise could be harmful (or, to speak more technically, what is the number needed to harm in exercise and those with depression?).


Medications and Use

“Anxiety About Antidepressants”

Roy H. Perlis

The American Journal of Psychiatry, 25 April 2018 Online First (Open Access)

A recent front-page New York Times article reframed a mental health success story into a conspiracy theory. The article, titled ‘Many People Taking Antidepressants Discover They Cannot Quit,’ presents public health population-level data indicating that, indeed, many people are taking antidepressants. Many researchers interpret this as indicating progress in the successful diagnosis and treatment of depression—and in particular, compliance with quality guidelines that emphasize treatment trials of adequate duration. However, the article instead juxtaposes these population data with anecdotes and small descriptive studies of individuals who have had difficulty discontinuing treatment. The argument moves from ecological fallacy to conspiracy when it implies that the paucity of longer-term data is by design. Mostly unspoken in the article is the sense that it can’t be good for all of these people to be taking these medications long term … can it?

Ironically, the Times article appeared only a week after a meta-analysis published by Cipriani and colleagues demonstrated, once again, this time based on data on more than 100,000 individuals, that antidepressants are generally similar to one another in efficacy and are consistently superior to placebo. Yet media accounts still routinely treat antidepressant efficacy as an open question and toxicity as a near certainty.

dsc_9943Roy H. Perlis

So opens a strong commentary piece from The American Journal of Psychiatry. The piece is concise, and doesn’t require much of a summary here.

The author takes aim at the suggestion that long-term use is problematic:

The informative analogy might be treatment of type 2 diabetes. While diet and exercise have a substantial impact on disease course (notably, results far more compelling than those in depression), it is hard to envision front-page articles in the New York Times about the dangers of long-term diabetes treatment. Instead, this article invites readers to make fallacious jumps connecting islands of truth in pursuit of a titillating, and stigma-perpetuating, theory: psychiatric disease and the suffering it brings are a failing of character best addressed through clean living or perhaps cleansed with redemptive suffering.

He also suggests that withdrawal is well known. “Factually, as the article acknowledges, withdrawal syndromes have been recognized from the beginning of the modern psychopharmacologic era.”

He concludes:

In short, the New York Times article buried the lead: the extent to which treatment of depression—whether pharmacologic, psychotherapeutic, or some combination—can truly change lives for the better. The increasing number of people receiving standard depression treatments in the United States represents the success of a substantial public health effort.

  1. This is surprisingly strong commentary for a major journal. (He is responding to The New York Times article which was considered in a past Reading. You can find it here:
  1. He makes good points, particularly about the long-term use of antidepressants.
  1. That said, his argument about people receiving care may be simplistic. Yes, many people are on antidepressant medication – and some do have depression and are being treated appropriately. But studies show that patients are both over-treated and under-treated. From a public-health perspective, much work is needed.


Reading of the Week. Every week I pick articles and papers from the world of Psychiatry.