Six-Month Stability and Outcome of a Prepubertal and Early Adolescent Bipolar Disorder Phenotype

OBJECTIVE: Six-month follow-up data are provided on a prepubertal and early adolescent bipolar disorder phenotype (PEA-BP). Stabilities were defined as continuous presence of PEA-BP and of individual mania criteria between baseline and 6 months. METHOD: Baseline and 6-month assessments of consecutively ascertained PEA-BP outpatients (n = 91) included comprehensive instruments given to mothers and children, separately, by research nurses; 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 mania criterion and to be definite cases by severity ratings. RESULTS: Of the 93 baseline subjects, 91 completed the 6-month assessment, for a retention rate of 97.8%. Baseline age was 10.9 +/- 2.7 years, and age of onset of current episode was 7.3 +/- 3.5 years. At 6 months, 85.7% still had full criteria and severity for mania or hypomania, and only 14.3% had recovered. Six-month stabilities of elated mood and grandiosity were high. Cox modeling and logistic regression did not show any significant effect of multiple covariates (e.g., gender, puberty, psychosis, mixed mania, rapid cycling, or naturalistic treatment). CONCLUSIONS: These longitudinal stability findings provide validation of a PEA-BP phenotype. Poor outcome was consistent with similarity of PEA-BP baseline characteristics to those of treatment-resistant adult-onset mania.