Familial correlates of central serotonin function in children with disruptive behavior disorders.

Previous findings suggest a relationship between childhood aggression, parental history of aggression and central serotonin (5-HT) function. The present study extended these findings by examining the impact of childhood aggression and central 5-HT function on the incidence of psychopathology in first- and second-degree relatives of pre-pubertal children with disruptive behavior disorders. Family history of psychopathology was obtained for 58 aggressive and 44 non-aggressive clinically referred children who were further sub-divided based on central 5-HT function. Central 5-HT function was assessed by measuring the prolactin response to a 1 mg/kg oral dose of d,l-fenfluramine. Aggressive children with low-prolactin responses to fenfluramine had a significantly greater incidence of first- and second-degree relatives with aggressive and antisocial characteristics compared to both non-aggressive children and aggressive children with high-prolactin responses. No group differences were found in the frequency of relatives with symptoms of cognitive impairment or inattention and hyperactivity. These data suggest that there are both familial and non-familial forms of aggression in children, and that only the familial type is associated with reduced 5-HT function.