Aripiprazole in Autism Spectrum Disorders and Fragile X Syndrome

Autism spectrum disorders (ASDs) are childhood onset developmental disorders characterized by impairment of social skills and repetitive behavior, and also for classic autistic disorder, a significant impairment of communication. In addition to these core symptom domains, persons with ASDs frequently exhibit interfering behavioral symptoms, including irritability marked by aggression, self-injurious behavior, and severe tantrums. Aripiprazole is an atypical or newer generation antipsychotic with a unique mechanism of action impacting dopaminergic and serotonergic neurotransmission. The drug has been found efficacious for several indications, including most recently for use targeting irritability associated with autistic disorder in youth. Fragile X syndrome is the most common inherited cause of developmental disability and the most common known single gene cause of ASDs. As in idiopathic ASDs, irritable behavior is often exhibited by persons with fragile X syndrome. However, research to date in this disorder has not focused on this target symptom cluster. An initial pilot study has begun to assess the impact of aripiprazole on irritability in youth with fragile X syndrome.