Researchers at the University of Alabama, Birmingham, looked at data from a longitudinal study of more than 5,000 men and women ages 18 to 30. Throughout the 20-year study, participants' waist circumference and body mass index were measured and they were asked about symptoms of depression.
"If you are interested in controlling obesity, and ultimately eliminating the risk of obesity-related diseases, then it makes sense to treat people's depression," the lead author of the study, Belinda Needham, said in a news release.
There is a possible physiological explanation why the two conditions occur together. Both conditions are linked to higher levels of the stress hormone cortisol.
The study is published in the American Journal of Public Health.