The idea that obesity is more closely linked to mental health than physical addictions has long been a pop psychology canard. Now new research is shedding new light on how depression in particular may be strongly linked with obesity.

A new study published in the International Journal of Obesity shows that this could be even more the case for teenage girls. The new research has found that young women who experience depression are at a higher risk for obesity as they age. The same, but opposite, is true for obese teen girls, who were found to be more at risk for depression.

“Adolescence is a key developmental period for both obesity and depression, so we thought it significant to look at the onset of these disorders at an early age,” said Naomi Marmorstein, a co-author of the study and an associate professor of psychology at Rutgers University-Camden. “When a person is young, she is still developing eating and activity patterns, as well as coping mechanisms. So if she experiences a depressive episode at age 14, she may be more at risk for having an onset of unhealthy patterns that persist.”

Marmorstein and her colleagues looked at a sample of more than 1,500 teens in Minnesota taken over ten years. The data shows that young women who encounter depression in their early adolescence are more at risk to become obese by the end of their teens. It also shows that women who are obese by the end of their teens are more at risk for depression during early adulthood.

The study also looked at adolescent boys, but did not find the same links between obesity and depression.

The study does not establish why young women in particular face such health concerns, but Marmorstein and her co-author did speculate a bit as to what the causes might be. She suggests that the teasing that is all too common among teenagers might contribute to depression in obese girls. And since the issues seem to go hand-in-hand, Marmorstein suggests that medical professionals consider treating both depression and obesity together.

“When an adolescent girl receives treatment for depression, the clinician might consider incorporating something relating to healthy eating and activity,” said Marmorstein. “Exercise can assist in the treatment of depression to begin with, so it seems like a good reason to combine prevention efforts for both depression and obesity.”