Long-term risperidone for pervasive developmental disorder: Efficacy, tolerability, and discontinuation

To investigate the safety (e.g., weight gain, liver function, extrapyramida l side effects, and seizures) and efficacy of the long-term use of risperid one in children and adolescents and to ascertain the effects of drug withdr awal in a semi-naturalistic prospective, subjects with autism or pervasive developmental disorders not otherwise specified (PDDNOS) were treated with risperidone for 6 months after which parents were given the option of conti nuing for a further 6 months (final assessment at 12 months). Behavioral ra ting included Childhood Autism Rating Scale (CARS), Child Psychiatric Ratin g Scale (CPRS), Clinical Global Impression (CGI), and Child-Global Assessme nt Scale (C-GAS). Risperidone significantly ameliorated behavioral symptoms of PDD in 10 out of 11 subjects, with the effects on core symptoms being o f smaller amplitude and of slower onset. No loss of effectiveness was obser ved in patients who continued risperidone for 12 months, while a relapse of associated behavioral symptoms occurred in the others. Weight gain was com mon, although the rate of increase lessened over a period of time; after dr ug withdrawal, considerable weight loss was observed in the patient who had previously shown the most significant increase. After 6 months of therapy, two patients developed facial dystonia: this disappeared after reducing do sage in one case, after drug discontinuation in the other. Amenorrhea was a lso observed, but no changes in liver function, blood tests or EEG were rep orted. The data indicate that risperidone is an effective and relatively sa fe drug for long term treatment of behavioral disruption in autistic childr en and adolescents.