Exercise, Depression, and Anxiety: The Evidence

I am Dr Drew Ramsey. I am an assistant clinical professor of psychiatry at Columbia University in New York City, and I am reporting for Medscape Psychiatry.

Exercise is one of those recommendations clinicians love, but what is the evidence that it can help our patients with depression? There are wonderful new data from the HUNT Cohort Study (Nord-Trøndelag Health Study), which followed over 33,000 healthy individuals in Nord-Trøndelag, Norway, starting around 1985.^[1]

This is a very interesting study if you are thinking about recommending exercise to your patients. First, the evidence is now quite clear that exercise can help with the prevention of depression, and it is also a recommendation that patients like and can participate in right away.

In the HUNT Study, 33,908 people were followed over 11 years.^[1] Initially, these participants were screened very carefully to ensure that they were healthy, had no preexisting history of depression, and were not actively depressed.

The investigators then measured individual exercise habits and found that even exercising 1 or 1.5 times a week had a significant effect in preventing depression. Over the course of the study, about 7% of participants became depressed, and almost 9% developed an anxiety disorder.

Interestingly enough, exercise did not protect against anxiety; however, exercise did have an effect on depression. The study investigators estimated that compared with individuals who did not exercise, those who exercised an hour or more a week had a 44% decreased odds ratio of becoming depressed—quite a significant finding.The researchers also noted that if depression was a causal factor, about 12% of cases could be prevented if all adults exercised for a little over an hour a week.^[1]

How will this affect your clinical practice? The first thing that I thought of was the lack of a finding for anxiety, and perhaps one of the reasons is because this a study of prevention. Exercise is one of the most clinically beneficial tools I have found clinically to help patients with anxiety, and patients often report feeling great after a workout. There are some data showing that anxiety can be helped or mitigated by regular exercise.^[2,3]

The findings on depression in the HUNT Study are quite exciting, and they give us a nice piece of evidence for our own education. The authors of the study do a very nice job talking about some of the physiologic factors. For example, individuals who exercise more have a better autonomic nervous system tone, meaning that their heart rate is a little bit slower. The authors also discuss other physiologic ways that exercise and physical conditioning can relate to depression.

It is a great study, and I encourage you to pick it up. I am also curious to know how you integrate exercise into your practice.

One of the other issues I considered was that even though we have known for a quite a while that exercise can be helpful in mitigating depression, it is not something that we often teach residents. It is not something that we often incorporate into practice. For example, in a standard psychiatric evaluation, assessing our patients' exercise routines and preferences is not something we are traditionally taught to do. I suggest that now the evidence tells us that we should, and I am really curious how you are incorporating these findings into your clinical practice.

I am Dr Drew Ramsey, from Medscape Psychiatry.

Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.

Cite this: Exercise, Depression, and Anxiety: The Evidence - Medscape - Mar 06, 2018.

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