by Brian Allred
During their lifetime, 7-12% of men will experience Major Depressive Disorder. The lifetime prevalence in women is even higher: approximately 20-25%.1 In fact, Major Depressive Disorder, or MDD, ranks second only to ischemic heart disease for years of life lost due to death or disability, but even with the risks involved, it is estimated that only 23% of people with MDD seek treatment and only 10% receive adequate treatment. In part, inadequate treatment occurs because of the social stigma associated with treatment.2
Currently, the majority of cases of MDD are treated with antidepressant medication. One major draw-back is the frequency of adverse side-effects. Although SSRIs cause less severe side-effects than either MAOIs or tricyclics, the side effects are more common in SSRIs.3
One of the alternatives to medication is physical exercise, which is inexpensive, easily available, and the side-effects of physical exercise are actually beneficial. Exercise is economical, easily offered, and valuable in other ways, including lowering blood pressure and cholesterol levels, decreasing fatigue, preventing both diabetes and CVD, maintaining healthy body weight, and many other benefits.
Studies consistently show less depression, anger, and stress in individuals who regularly exercise versus those who do not.4 You might ask how much and what kind of exercise is best. I’ll put some of the nerdy stuff at the bottom, but the bottom line is at least 3 times a week at moderate intensity. The intensity seems to be more important than the frequency. Seems pretty easy, right? The tricky part is that although there is an abundance of evidence demonstrating exercise’s effectiveness in treating depression, it is much more difficult to implement in practice for a variety of reasons. Exercise maintenance is difficult even for those who are physically and emotionally healthy—less than half continue after six months.5 In addition, depressed individuals are often lacking in both energy and motivation, which compounds the problem making them even less likely to adhere to an appropriate exercise program. Additionally, depressed individuals are more likely to feel overwhelmed, focus on barriers, minimize their progress, and experience low self-efficacy making them more likely to drop out. Here are some bullet points that might help:
- Ask for help. When starting a prescribed exercise program, initial assistance with the fitness center is critical to overcome the intimidation of setting up appointments, asking questions, etc.
- Include activities that you enjoy. A game of pickleball might be a better choice for you than running on a treadmill.
- Set goals.
- If you need to start slow, that’s OK. It’s better to make an easy plan that you will keep, than to go all out right away and burn out.
- Don’t be afraid of failing—at least in the short term. It’s important to remember that lapses are likely, but they are not devastating to the program.
- Remember that exercise can be accumulated—three 10-minute bouts are as good as one 30-minute bout.5
- Follow up. If you are having help from someone like your physical therapist, make sure to follow up, even if it is just a brief phone call. Follow up should include reinforcement, problem-solving, and goal modification if necessary.5
The Research
Here’s the nerdy stuff I promised earlier: Dunn et al.2 investigated the effects of different amounts of exercise on depression. They studied the effects of both frequency (either 3 or 5 days/week) and intensity (either 7.0 or 17.5 kcal/kg/week on treadmill or stationary bike). They used the 17-item Hamilton Rating Scale for Depression, or HRSD17, as a marker because it measures the severity of symptoms and it is broadly used in pharmaceutical trials.
While frequency of exercise did not seem to make a difference, higher intensity exercise produced the greatest improvement. The baseline mean was a HRSD17 score of 16.2 which was decreased after 12 weeks to an HRSD17 score of 9.5 in the 17.5 kcal/kg/week groups as opposed to a score of 12.3 in the 7.0 kcal/kg/week groups. These data imply that exercising aerobically at least three days/week at an intensity of 17.5 kcal/kg/week is most effective in treating depression. This intensity corresponds to the guidelines established by the American College of Sports Medicine and can be considered “moderate intensity.” Concerning the effects of aerobic exercise versus anaerobic exercise, Stathopoulou et al.4 declare that even though only a few studies have been performed comparing aerobic and anaerobic exercises in the treatment of depression, studies reliably find no significant difference between the two.
References:
1. American Psychiatric Association. (1994). Diagnostic and Statistical Manual of Mental Disorders (4th ed.). Washington, DC: American Psychiatric Association.
2. Dunn, A. L., Trivedi, M. H., Kampert, J. B., Clark, C. G., Chambliss, H. O. (2005). Exercise treatment for depression: Efficacy and dose response. American Journal of Preventive Medicine, 28, 1-8.
3. Kirsch, I., Scoboria, A., & Moore, T. J. (2002). Antidepressants and placebos: Secrets, revelations, and unanswered questions. Prevention & Treatment, 5, 33.
4. Stathopoulou, G., Powers, M. B., Berry, A. C., Smits, J. A. J., & Otto, M. W. (2006). Exercise interventions for mental health: A quantitative and qualitative review. Clinical Psychology: Science and Practice, 13, 179-193.5. Seime, R. J. & Vickers, K. S. (2006). The challenges of treating depression with exercise: From evidence to practice. Clinical Psychology: Science and Practice, 13,194-197.
Brian Allred, PT, DPT
Physical Therapist