Exercise, Depression, Gender & Genetics
Gender and specific genetic markers seem to influence whether exercise can help a person improve depression symptoms, according to a pilot study conducted by researchers from the University of Florida, Gainesville.
“If we show through systematic research that exercise has a good chance of helping patient[s] because of their particular characteristics, I think that might help with patients’ motivation to exercise,” said Vonetta Dotson, PhD, assistant professor in the College of Public Health and Health Professions’ department of clinical health psychology and the study’s lead author, in a University of Florida news release. “I want to better understand who could benefit most from physical activity,” said Dotson. “I’d like to take the same approach to exercise that we take to medication, which is to have a personalized medicine approach.”
Dotson and colleagues based their findings on analysis of data from the Lifestyle Interventions and Independence for Elders Pilot Study. In that study, researchers divided 396 sedentary adults (aged 70–89) into two groups—a control group, which received health education classes, and an exercise group—and followed them for a year. Before and after the intervention, participants took a screening test for depression and depressive disorders. It assessed symptoms of sadness and fearfulness; symptoms like loss of appetite and concentration difficulties; diminished capacity to experience pleasure; and perceived difficulties in social relationships. Participants also underwent genetic testing.
Exercise benefited some but not all of the subjects with depressive symptoms. Data analysis revealed that the greatest decrease in symptoms like loss of appetite and difficulties with concentration occured in male subjects with a genetic variation in the brain-derived neurotrophic factor, or BDNF, gene. Male participants with a specific variation of the serotonin transporter gene increased their capacity to experience pleasure more than female participants did, in both the exercise and education groups.
Study authors agreed that more research is necessary, since these findings are from pilot studies. Dotson said, “I’m trying to understand how exercise versus antidepressants affect the brain. The next step for me is to understand from a brain standpoint who is going to benefit and how exercise is going to be beneficial in addition to, or as an alternative to, medication.”
The study is available in The Journal of Frailty & Aging (2016; 5 [1], 6–14).