Patterns of Comorbidity and Dysfunction in Clinically Referred Preschool and School-Age Children with Bipolar Disorder

Objective: Despite its common onset in preschool years, few studies have examined the characteristics of bipolar disorder (BPD) in preschoolers. This study reports on the clinical characteristics, psychiatric comorbidity, and functioning of preschoolers identified with BPD who were referred to a pediatric psychiatric clinic. Methods: Structured psychiatric interviews assessing lifetime psychopathology by Diagnostic and Statistical Manual of Mental Disorders (third edition, revised) criteria were completed with parents about their children and confirmed by clinical interview of the child. Family, social, and overall functioning were also assessed at intake. Findings from preschoolers ages 4 to 6 years were compared with a group of children ages 7 to 9 years (school age). Results: We identified 44 preschoolers and 29 consecutively ascertained school-age youth with BPD. Preschoolers had similar rates of comorbid psychopathology compared to school-age youth with BPD. Preschoolers and school-age children with BPD typically manifest symptoms of mania and major depression simultaneously (mixed states). Both preschoolers and school-age children had substantial impairment in school, social, and overall functioning. Conclusions: These results suggest that clinically referred preschoolers with BPD share with school-age children with BPD high rates of comorbid psychopathology and impaired functioning. Follow-up of these clinically referred preschoolers with BPD evaluating the stability of their diagnoses, treatment response, and their long-term outcome is necessary.