Selective serotonin reuptake inhibitors in autism: A review of efficacy and tolerability

Background: Awareness of the impact and prevalence of autism spectrum disorders has significantly increased in recent years. Given the dearth of reliable interventions, there is great interest in demonstrating efficacy of the various treatment options. A growing body of evidence links autism spectrum disorders to abnormalities in serotonin function, and the selective serotonin reuptake inhibitors (SSRIs) have been utilized to target various symptoms of the disorders. This article reviews the available data on the efficacy and tolerability of SSRIs in individuals with autism spectrum disorders. Objectives for future research in this area will also be suggested. Data Sources and Study Selection: The entire PubMed database including MEDLINE (1966-July 2005) was searched for English-language biomedical articles. Search terms included autism, autism spectrum disorder, citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, pervasive developmental disorder, selective serotonin reuptake inhibitors, and sertraline. All clinical trials evaluating treatment outcomes associated with the use of SSRIs in managing symptoms of autism that were identified in the search were reviewed. All randomized controlled trials and open-label trials were included in this review. Case reports and case series were excluded. Data Synthesis: We identified 3 randomized controlled trials and 10 open-label trials or retrospective chart reviews on the use of SSRIs in autism and autism spectrum disorders. The SSRIs that have been studied in autism spectrum disorders are citalopram, escitalopram, fluoxetine, fluvoxamine, and sertraline. Most studies demonstrate significant improvement in global functioning and in symptoms associated with anxiety and repetitive behaviors. While side effects were generally considered to be mild, increased activation and agitation occurred in some subjects. Conclusions: Although SSRIs may demonstrate therapeutic benefit in autism spectrum disorders, methodological weaknesses of many of the clinical trials suggest the need for additional randomized controlled trials. Furthermore, given the increased awareness of the dangers associated with SSRI-induced activation and agitation, the presence of these side effects in the autistic population warrants closer attention to dosage, titration, and subject selection issues.