Serotonergic functioning in children with oppositional defiant disorder: a sumatriptan challenge study.

BACKGROUND Several studies support the notion that disturbances in the central serotonergic function are related to impulsive aggression. There is recent evidence from studies on 5-HT(1B) knock-out mice that this specific receptor is involved in impulsive aggressive behavior. The aim of the present study was to investigate 5-HT(1B/1D) receptor functioning in normal intelligent hospitalized children with oppositional defiant disorder (ODD). METHODS The growth hormone (GH) response to a challenge with the 5-HT(1B/1D) agonist sumatriptan was examined in 20 children with an ODD, of whom 13 had an attention-deficit/hyperactivity disorder comorbidity, and 15 normal control subjects (NC). Blood samples for growth hormone were collected repeatedly between 8:30 and 12:00 AM. Sumatriptan was administered at 10 AM. The effect of stress due to this procedure was assessed by measuring salivary cortisol. RESULTS The GH response was significantly stronger in the children with ODD. After sumatriptan injection NC children showed a significant increase in cortisol; no such pattern was present in the ODD group. CONCLUSIONS The results suggest that the postsynaptic 5-HT(1B/1D) receptor is functionally more sensitive in children with ODD.