Diagnostic characteristics of 93 cases of a prepubertal and early adolescent bipolar disorder phenotype by gender, puberty and comorbid attention deficit hyperactivity disorder

Etiopathogenetic and treatment studies require homogeneous phenotypes. Therefore, effects of gender, puberty, and comorbid attention deficit hyperactivity disorder (ADHD) on DSM-IV mania criteria and other characteristics of a prepubertal and early adolescent bipolar disorder (PEA-BP) phenotype were investigated. Consecutively ascertained PEA-BP (with or without comorbid ADHD) outpatients (n = 93) were blindly assessed by research nurses with comprehensive instruments given to mothers and children separately, consensus conferences, and offsite blind best estimates of both diagnoses and mania items. To fit the study phenotype, subjects needed to have current DSM-IV mania or hypomania with elated mood and/or grandiosity as one criterion and to be definite cases by severity ratings. Subjects were aged 10.9 +/- 2.6 years, had current episode length of 3.6 +/- 2.5 years, and had early age of onset at 7.3 +/- 3.5 years. No significant differences were found by gender, puberty, or comorbid ADHD on rates of mania criteria (e.g., elation, grandiosity, racing thoughts), mixed mania, psychosis, rapid cycling, suicidality, or comorbid oppositional defiant disorder (ODD), with few exceptions. Subjects with comorbid ADHD were more likely to be younger and male. Pubertal subjects had higher rates of hypersexuality. These findings support that the PEA-BP phenotype is homogeneous except for differences (hyperactivity, hypersexuality) that mirror normal development.