Objective: Obesity and major depressive disorder (MDD) are associated, but evidence about how they relate over time is conflicting. The goal of this study was to examine prospective associations between depression and obesity from early adolescence through early adulthood. Methods: Participants were drawn from a statewide, community-based, Minnesota sample. MDD and obesity with onsets by early adolescence (by age 14), late adolescence (between 14 and 20) and early adulthood (ages 20-24) were assessed via structured interview (depression) and study-measured height and weight. Results: Cross-sectional results indicated that depression and obesity with onsets by early adolescence were concurrently associated, but the same was not true later in development. Prospective results indicated that depression by early adolescence predicted the onset of obesity (odds ratio (OR)=3.76, confidence interval =1.33-10.59) during late adolescence among female individuals. Obesity that developed during late adolescence predicted the onset of depression (OR=5.89, confidence interval =2.31-15.01) during early adulthood among female individuals. Conclusions: For girls, adolescence is a high-risk period for the development of this comorbidity, with the nature of the risk varying over the course of adolescence. Early adolescent-onset depression is associated with elevated risk of later onset obesity, and obesity, particularly in late adolescence, is associated with increased odds of later depression. Further investigation into the mechanisms of these effects and the reasons for the observed gender and developmental differences is needed. Prevention programs focused on early-onset cases of depression and adolescent-onset cases of obesity, particularly among female individuals, may help in reducing risk for this form of comorbidity.
Bibliographical noteFunding Information:
This research was supported by the following grants from the National Institutes of Health: DA022456, DA05147 and AA09367.