Paroxetine treatment of aggression and self-injury in persons with mental retardation.

An open, prospective assessment of the treatment of severe aggression and self-injurious behavior (SIB) with paroxetine, a serotonin re-uptake inhibitor, in 15 institutionalized persons with mental retardation was undertaken. Frequency and severity of aggression and SIB were charted by trained staff members. Only aggression severity was reduced over the entire 4-month follow-up period. Within the limits of an open trial, this effect was significant at one month but did not remain significant subsequently. The apparent diminution of effectiveness after 4 weeks of treatment may suggest adaptive changes warranting further study.