Objective: The purpose of this study is to analyze the developmental relationships of adolescent-onset Axis I mental disorders and eating disorders (EDs).
Method: One thousand three hundred eighteen adolescent twins born from 1983 to 1987 completed a professionally administered semistructured psychiatric interview at the age of 14 years and a questionnaire follow-up at the age of 17.5 years.
Results: Eating disorders at the age of 17.5 years were significantly predicted by major depressive disorder (odds ratio, 5.9; 95% confidence interval, 2.6-15.3) and generalized anxiety disorder (GAD) (odds ratio, 4.7; 95% confidence interval, 1.8-15.6) at the age of 14 years, when baseline EDs were excluded. Early-onset major depressive disorder in combination with GAD increased the likelihood of developing EDs compared with either mood or anxiety disorders alone. Similar risks and trends were evident in within-family analyses of twin pairs discordant for baseline predictors and ED outcome.
Conclusions: Depressive disorder and GAD that manifest at that age of 14 years predict future EDs. Analysis of discordant twins suggested that early-onset depressive disorder and GAD prospectively relate to EDs in adolescence, even after familial factors are taken into account. (C) 2009 Elsevier Inc. All rights reserved.