Neurodevelopmental antecedents of early-onset bipolar affective disorder.

Background: Developmental impairments have been identified as a risk factor for early-onset schizophrenia. Affective symptoms are more common in children and adolescents with disordered neurodevelopmental than in healthy controls.

Aims: To test the hypothesis that severe early-onset mood disorders are associated with developmental antecedents.

Method: We retrospectively identified 38 adolescent cases (15 female, 23 male; mean age 14.4 years, range 11-18) who met ICD-10 Research Diagnostic Criteria for a manic episode, bipolar affective disorder or psychotic depression, and 41 controls (25 female, 16 male, mean age 14.2 years, range 11-18) with depression but without psychotic features.

Results: Cases were significantly more likely to have experienced delayed language, social or motor development (OR 5.5, 95% CI = 1.4-21.6, P = 0.01), in particular those who develop psychotic symptoms (OR 7.2, 95% CI = 1.8-28.6, P = 0.003).

Conclusions: Compared to early-onset unipolar depression, neurodevelopmental antecedents are over-represented in early-onset bipolar disorder. The validity of this finding was supported by contemporaneous IQ scores that are not subject to the same potential biases as case-note ratings.