Severe obesity not seen to increase risk of depression in teens

This three-year study -- performed by researchers from the Center for Child and Adolescent Health Policy at Mass General Hospital for Children (MGHfC) and the Department of Public Health and Community Medicine at Tufts Medical School -- analyzed the relationship between severe obesity and depressive symptoms in a community-based sample of non-Hispanic black and white adolescents.

"People assume that all obese adolescents are unhappy and depressed; that the more obese a teen may be, the greater the impact on his or her mental health," says Elizabeth Goodman, MD, the lead author of the study and the director of the Center for Child and Adolescent Health Policy. "Our findings suggest this assumption is false."

The study included 51 severely obese participants (body mass index greater than or equal to 40 and higher than 95 percent of their age group), between grades 7-12 and an equal number of non-obese participants matched for age, gender and race. Depressive symptoms were analyzed using a standard assessment tool at the study outset and reassessed two and three years later. Participants were defined as having high depressive symptoms if they used antidepressant medication or had assessment scores at or above a level known to predict major depressive disorder.

Unlike other investigations, which included participants from obesity treatment clinics, the study found no relationship between participants' weight status and the likelihood of being depressed. The authors note that obese teens coming to a clinic for treatment are likely to feel worse about their body size and shape than those not seeking treatment. Because this study was community- and not clinic-based, the findings may more generally reflect young people's feelings. An association between obesity and higher depressive symptoms was seen, but only in white participants and only at the three-year assessment, not at baseline or at two years.

"As clinicians, we treat the entire person -- body and mind -- and we can't assume that weight loss will improve all our patients' mental health or that negative feelings run hand-in-hand with obesity," says Goodman who is a visiting professor of Pediatrics at Harvard Medical School. "Body size appears to have a greater impact on feelings of non-Hispanic White teens' than non-Hispanic black teens. We should be particularly vigilant about assessing for depression during regular visits among this group"

The study was made possible by grants from the National Institutes of Health and the Richard Saltonstall Fund.