Lifetime Psychiatric Disorders in School-aged Offspring of Parents With Bipolar Disorder: The Pittsburgh Bipolar Offspring Study

Abstract

CONTEXT: Whether offspring of parents with bipolar disorder (BP) are at specifically high risk to develop BP and other psychiatric disorders has not been adequately studied. OBJECTIVE: To evaluate lifetime prevalence and specificity of psychiatric disorders in offspring of parents with BP-I and BP-II. DESIGN: Offspring aged 6 to 18 years who have parents with BP and community control subjects were interviewed with standardized instruments. All research staff except the statistician were blind to parental diagnoses. SETTING: Parents with BP were recruited primarily through advertisement and outpatient clinics. Control parents were ascertained by random-digit dialing and were group matched for age, sex, and neighborhood to parents with BP. PARTICIPANTS: Three hundred eighty-eight offspring of 233 parents with BP and 251 offspring of 143 demographically matched control parents. MAIN OUTCOME MEASURES: Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) Axis I disorders. RESULTS: Adjusting for demographic factors, living with 1 vs both biological parents, both biological parents' non-BP psychopathology, and within-family correlations, offspring of parents with BP showed high risk for BP spectrum disorders (odds ratio [OR] = 13.4; 95% confidence interval [CI], 2.9-61.6) and any mood (OR = 5.2; 95% CI, 2.3-11.4), anxiety (OR = 2.3; 95% CI, 1.3-4.0), and Axis I (OR = 2.2; 95% CI, 1.5-3.3) disorders. Offspring of parents with BP with high socioeconomic status showed more disruptive behavior disorders and any Axis I disorders than offspring of control parents with high socioeconomic status. Families in which both parents had BP had more offspring with BP than families with only 1 parent with BP (OR = 3.6; 95% CI, 1.1-12.2). More than 75.0% of offspring who developed BP had their first mood episode before age 12 years, with most of these episodes meeting criteria for BP not otherwise specified and, to a lesser degree, major depression. CONCLUSIONS: Offspring of parents with BP are at high risk for psychiatric disorders and specifically for early-onset BP spectrum disorders. These findings further support the familiality and validity of BP in youth and indicate a need for early identification and treatment.