Research Quantifies Benefits of Exercise Against Depression

June 16, 2013

exercise against depression

by Jessica Josh

 

We all heard that: exercise to avoid or alleviate depression. For years, mental healthcare providers have universally agreed on the merits of exercise as complimentary therapy for depression. But no clinical research has been performed in order to quantify its power over mental illness. Until now.

 

In the May issue of the Journal of Psychiatric Practice, psychiatrists from the University of Texas Southwestern Medical Center in Dallas reported unprecedented research findings on benefits of physical activity for treating clinical depression, known in medical parlance as major depressive disorder (MDD).

 

“Despite the substantial evidence supporting the use of exercise in the treatment of MDD, previous studies have not provided a clear indication of the proper dose of exercise needed to elicit an antidepressant effect,” wrote authors Chad Rethorst, PhD, and Madhukar Trivedi, MD.

 

According to World Health Organisation, depression afflicts around 350 million people worldwide, with 9 million adults in the US alone suffering from clinical depression.

 

Specific guidance

 

Reviewing findings from existing randomised trials, the authors found that exercise is indeed an effective antidepressant, either by itself or in conjunction with drugs and psychotherapy, among other treatments. These trials also suggest that MDD patients respond optimally to aerobic exercise and, to an extent, resistance training.

 

Based on statistical results of their study, Rethorst and Trivedi recommend depression patients to aim for 50 to 85 percent of their HRmax (maximum heart rate) when performing aerobic activities. They also prescribed weight training at 80 percent of 1-RM (repetition maximum); three sets of eight repetitions involving both lower- and upper-body muscle groups are adequate.

 

All in all, MDD sufferers should clock in three to five exercise sessions weekly, with each session lasting 45-60 minutes. However, Rethorst and Trivedi warned that measurable health benefits can manifest within four weeks of starting the regimen.

 

Granted, clinical psychologists argue that exercise of any frequency and intensity is better than doing nothing at all. Even in the study by Trivedi and Rethorst 15 percent of patients did not finish the physical activity regimens required by the trials. So, why does it work? Physical exercise increases the rate at which serotonin (aka “hormone of happiness”) is generated by the brain, thus causing the increase in release and synthesis of serotonin.

 

 

Stubborn depression

 

Alas, even the best treatments may prove futile against depression. Sometimes other conditions, can aggravate it. Bipolar disorder, thyroid disorders, cardiovascular ailment, and anemia have all been known to make depression resistant to treatment.

 

Psychiatrists may prescribe, in addition to antidepressants, medications indicated for other mental illnesses, e.g. mood stabilizers, stimulants, and antipsychotics. They may also request a cytochrome P450 genotyping test, which tells if the patient can efficiently metabolize a drug.

 

Clinical psychologists are essential participants in the treatment of depression. Psychodynamic treatment, a relatively drastic kind of psychotherapy, helps the sufferer dig up deep-seated beliefs and feelings that contribute to the depression. This method obviously takes time but, unlike medication, it arms the patient with tools to avoid depression in the future.

 

It is rarely used nowadays, but if worse comes to worst, psychiatrists may proffer options like transcranial magnetic stimulation and electroconvulsive therapy (ECT), both of which make use of electric currents.

 

In the former, a large coil builds magnetic fields that affect the mood-controlling parts of the brain. ECT, on the other hand, offers stopgap relief from severe depression by practically passing electricity through the brain; patients experience a seizure each time.

 

Author Bio: Jessica Josh is an Australian freelance writer and blogger.  Since 2007 she has been writing about health and nutrition and fitness, and articles for  Northshore Health & Fitness

 Image Credit: Mark Sebastian