Atypical antipsychotics in persons with developmental disabilities

The introduction of clozapine spawned the development of several novel anti psychotic agents during the last decade. Compared to traditional agents, th ese "atypical antipsychotics" demonstrate more favorable characteristics in terms of efficacy and medication-associated abnormal involuntary movements . Several underlying neurochemical mechanisms have been posited for the dif ferences noted between traditional and atypical antipsychotic drugs. Most t heories have been based on the observation that atypical agents have higher affinities and greater selectivity for different dopamine receptor subtype s and for serotonin receptors. In addition, there is speculation about the involvement of other types of neurotransmitters (e.g., gamma-aminobutyric a cid, N-methyl-D-aspartate) in the actions of these drugs. A review of the c urrent literature on the developmental disabilities indicated that the stud y populations can be divided into three general categories: (a) individuals with mental retardation and a psychiatric syndrome; (b) individuals with m ental retardation and behavioral problems; and (c) individuals with autism and other pervasive developmental disorders. The atypical antipsychotics mo st consistently appeared to reduce symptoms of self-injury, aggression, agi tation, and repetitive behaviors. It is not yet clear whether they enhance prosocial behavior, although findings of some reports suggested this. A cle ar limitation of the available evidence is that few studies are methodologi cally sound. Suggestions for further research are offered. (C) 1999 Wiley-L iss, Inc.