Manic symptoms in youth with bipolar disorder: factor analysis by age of symptom onset and current age

Factor analysis has been used to identify potential clinical subtypes of mania in pediatric bipolar disorder. Results vary in the number of factors retained. The present study used a formal diagnostic instrument to examine how symptoms of mania in young people are expressed, depending on age of symptom onset and current age.

Trained clinicians completed the Schedule of Affective Disorders and Schizophrenia for School-Age Children (K-SADS) Mania Rating Scale (MRS) with parents of 163 children with child-onset of symptoms (before age 12), 94 adolescents with child-onset of symptoms, and 90 adolescents with adolescent-onset of symptoms (after age 12). Factor analysis of symptom ratings during the most severe lifetime manic episode was performed for each age group.

Symptom factor structures were established for each age group. Two factors were evident for children with child-onset of symptoms ("activated/pleasure seeking" and "labile/disorganized"), one factor was present for adolescents with child-onset of symptoms ("activated/pleasure seeking/disorganized") and two factors were evident for adolescents with adolescent-onset of symptoms ("activated/pleasure seeking" and "disorganized/psychotic"). The factor structures for children with child-onset and adolescents with adolescent-onset of symptoms were highly similar, with the latter factor structure including psychotic symptoms.

Limitations include reliance on retrospective parent report and potential issues with generalizability.

Findings suggest mania symptomatology is largely similar when examined by both age of onset and current age, with some notable differences. Specifically, psychotic symptoms begin emerging as a distinct factor in adolescents with adolescent-onset of symptoms.