To assess prior diagnoses and to allow for continuous follow-up, children were required to have at least one of their bipolar diagnoses between July 1, 2005 and December 31, 2006 (hereafter called the index diagnosis date). Children with incident and prevalent diagnoses who were continuously enrolled for 180 days prior to and 365 days following their index diagnosis date were included (N = 7,119). From this sample, children with conditions that mimic symptoms of mania, (multiple sclerosis, hyperthyroidism, closed or open head injury, lupus), require a bipolar-related treatment (epilepsy), or complicate bipolar disorder treatment (pregnancy) (11, 31) were excluded, as were children with schizophrenia, pervasive developmental disorders, mental retardation, or substance abuse disorders in the 180 days prior to their first bipolar diagnosis (n = 1,011).(32) Finally, children whose insurance plans did not provide information on medication use were excluded to differentiate between non-use and non-reporting of medications (n = 1,135).
