Research into the pharmacotherapy of individuals with pervasive developmental disorders (PDDs) has increased steadily over the last 20 years, and more rapidly over the last several years, as treatment successes have triggered more rigorous study. The use of drugs targeted to possible neurochemical systems involved in the pathophysiology of autistic disorder (autism) have been shown to often reduce aggression, self-injury, and interfering repetitive behavior in these patients (Cook, 1990). No pharmacotherapeutics have yet shown a consistent primary effect on the core social disability of autism. Combined with comprehensive individualized treatment programs, appropriate pharmacotherapy can enhance an autistic person's ability to benefit from educational and behavior modification techniques (McDougle et al., 1994). This chapter will comprehensively highlight significant research in the psychopharmacology of PDDs from the perspective of specific neurochemical systems.
Drug treatment studies focusing on subtypes of PDD, other than autism, have not yet been conducted (McDougle, 2002). Many trials thus far have used heterogeneous samples, including individuals with autism, Asperger's disorder, and PDD not otherwise specified (PDD-NOS). As appropriate, differences in drug response among patients with different PDD subtypes will be highlighted. Because of their rarity, little systematic pharmacologic research has occurred in subjects with Rett's disorder or childhood disintegrative disorder.