Prospective associations of early-onset Axis I disorders with developing eating disorders

The purpose of this study is to analyze the developmental relationships of adolescent-onset Axis I mental disorders and eating disorders (EDs).

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.

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.

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.