A cohort study of the prevalence and impact of comorbid medical conditions in pediatric bipolar disorder.

OBJECTIVE: To identify the association between medical or psychiatric comorbidities, clinical characteristics, or course of illness/recovery in pediatric bipolar disorder (BD).
METHOD: Data from the South Carolina Medicaid program covering all medical services and medication prescriptions between January 1996 and December 2005 were used to analyze the temporal onset of 12 comorbid medical or psychiatric conditions for 1,841 children and adolescents diagnosed with BD using DSM-IV-TR criteria and for a random sample of 4,500 children not treated for psychiatric disorders. The primary outcome measures were diagnostic codes and regression analyses of patterns of acute and outpatient treatment services for BD over time.
RESULTS: Ten conditions examined were significantly more prevalent in the BD cohort: obesity, type 2 diabetes mellitus, endocrine disorders, migraine headaches, central nervous system (CNS) disorders/epilepsy, organic brain disorders/mental retardation, cardiovascular disorders, attention-deficit/hyperactivity disorder (ADHD), asthma, and substance abuse (P ≤ .01). For clinical characteristics within the BD cohort, an adolescent-onset diagnosis of BD (age ≥13 years) was significantly associated with the diagnosis of preexisting obesity, hypertension, migraine, mental retardation, endocrine disorders, and substance abuse (P ≤ .05), whereas recurrent depressive episodes were associated with preexisting endocrine disorders and substance abuse. Preexisting ADHD, substance abuse, CNS disorders/epilepsy, cardiovascular disorders, obesity, and asthma were associated with higher overall medical and psychiatric outpatient and acute service use, but none of these comorbid disorders differentially impacted the course of illness or recovery for BD.
CONCLUSIONS: Neuropsychiatric (ie, ADHD, substance abuse, CNS disorders/epilepsy) and medical (ie, obesity, asthma, cardiovascular disease) disorders temporally precede the diagnosis of early-onset BD in pediatric patients and are associated with discrete facets of illness presentation, but they do not substantially alter the clinical course of the BD over time. © Copyright 2010 Physicians Postgraduate Press, Inc.