Is there progression from irritability/dyscontrol to major depressive and manic symptoms? A retrospective community survey of parents of bipolar children.

BACKGROUND: Although previous studies have discussed age-related changes in the presentation of early onset bipolar illness, the developmental progression of early symptoms remains unclear. The current study sought to trace parents' retrospective report of yearly occurrence of symptoms in a sample of children with and without a diagnosis of bipolar disorder in the community.
METHODS: Parents retrospectively rated the occurrence of 37 activated and withdrawn symptoms causing dysfunction for each year of their child's life (mean age 12.6 +/- 6.9). Children were divided into three groups based on parent report of diagnosis by a community clinician: bipolar (n=78); non-bipolar diagnosis (n=38); and well (no psychiatric diagnosis) (n=82). Principal components analysis was performed to understand the relationship among the symptom variables and their potential differences among the three groups as a function of age.
RESULTS: Four symptom components were derived and these began to distinguish children with bipolar disorder from the other groups at different ages. Component II (irritability/dyscontrol), which included temper tantrums, poor frustration tolerance, impulsivity, increased aggression, decreased attention span, hyperactivity and irritability, began to distinguish bipolar children from the others the earliest (i.e., from ages 1 to 6). The other components (I, III, and IV) which included symptoms more typical of adult depression (I), mania (III), and psychosis (IV), distinguished the children with a bipolar diagnosis from the others much later (between ages 7 and 12). LIMITATIONS: The data were derived from retrospective reports by parents of their children's symptoms on a yearly symptom check list instrument which has not been previously utilized. Parents' ratings were not validated by an outside rater. Moreover, the children were diagnosed in the community and a formal diagnostic interview was not given.
CONCLUSIONS: By parental report, the cluster of symptoms in the irritability/dyscontrol component may characterize the earliest precursors to an illness eventually associated with more classic manic and depressive components that are diagnosed and treated as bipolar disorder in the community. These retrospective survey data suggesting a longitudinal evolution of symptom clusters in childhood bipolar-like illness identify a number of areas for prospective research and validation.