"It could be that, in this population, important mental health benefits can be gained by simply not being sedentary," King noted.
The study authors pointed out that more research is needed to prove that patients' physical activity influences their mental health.
"Results of the study are provocative, but we would need further research to verify that physical activity was responsible for lower levels of depressive symptoms in this patient population," said study co-author Melissa Kalarchian, an associate professor at Western Psychiatric Institute and Clinic of UPMC in the news release. "Nonetheless, physical activity is a key component of behavioral weight management, and it is encouraging to consider that it may have a favorable impact on mental health as well."
While 7 percent of the general population has major depressive disorder and 10 percent has anxiety disorder, adults who are severely obese are nearly twice as likely to be affected by these conditions.
The researchers said that depression and anxiety should be treated before weight-loss surgery, since these mental health issues can have a negative impact on long-term surgically induced weight loss.
The study was published in the February issue of the Journal of Psychosomatic Research.
The U.S. Centers for Disease Control and Prevention provides more information on the benefits of physical activity.
-- Mary Elizabeth Dallas
SOURCE: University of Pittsburgh Medical Center, news release, Feb. 14, 2013
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