Surveys indicate that nearly half of children with autism spectrum disorders take some type of psychiatric medication — most often antidepressants, antipsychotics, or stimulants. Yet a federally funded study concluded that most of these drugs aren't effective at treating symptoms of autism spectrum disorders.

Although estimates vary, about one in 110 U.S. children has an autism spectrum disorder. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) describes five: autistic disorder, Asperger's disorder, Rett's disorder, childhood disintegrative disorder, and pervasive developmental disorder not otherwise specified. While autism spectrum disorders differ in some ways, they all cause impairment in the ability to communicate, socialize, and build relationships. Individuals with these disorders may also engage in ritualistic or repetitive behaviors like constantly tapping their fingers or humming.

Early intervention behavioral therapy, typically delivered at home or in school, forms the foundation of treatment for autism spectrum disorders. Unfortunately these therapies are labor- and time-intensive, producing modest improvements at best. Parents and clinicians, often desperate for additional options, have increasingly turned to medications to alleviate symptoms such as aggression, irritability, and repetitive behaviors, or to prevent children from injuring themselves.

In an effort to provide clinicians and parents with better information to guide treatment decisions, the U.S. Agency for Healthcare Research and Quality asked investigators at the Vanderbilt University Evidence-Based Practice Center to conduct a review of research on various autism spectrum disorder treatments for children 12 and younger.

Secretin flops

The hormone secretin stimulates the secretion of digestive fluids. In 1998, case reports of three children with autism spectrum disorders who were given secretin during medical procedures suggested that secretin improved thinking ability and communication skills. However, the Vanderbilt reviewers examined seven randomized controlled studies conducted since then and found that none of them showed that secretin is helpful for children with autism spectrum disorders. (An earlier review by the Cochrane Collaboration concluded the same thing.) As such, there is no reason to use secretin — although some Web sites still promote it.

Limited impact on behavior

The review found that no medications improve social skills or communication ability in children with autism spectrum disorders. Some drugs may modestly improve their behavior.

Antipsychotics - Intwo studies of risperidone (Risperdal), for example, investigators asked parents to rate their children's behavior using a 48-point checklist (the higher the score, the worse the behavior). Scores dropped an average of 12 to 15 points in children treated with risperidone, compared with an average drop of 4 to 7 points in children assigned to placebo. Parents reported that risperidone also reduced repetitive behavior and hyperactivity in their children. Two studies of aripiprazole (Abilify) reported similar results.

Both antipsychotics caused significant side effects, including weight gain, sedation, and extrapyramidal symptoms (such as muscle stiffness or tremor). The Vanderbilt reviewers recommended that risperidone and aripiprazole be used only when children with autism spectrum disorders are severely impaired or at risk of injuring themselves.

Other drugs.The review concluded there is scant evidence that antidepressants help improve behavior in children with autism spectrum disorders. And they identified only one good-quality randomized controlled study of methylphenidate (Ritalin) in youths with autism spectrum disorders. Although this study found that the drug reduced hyperactivity in participants, this benefit was offset by side effects such as lethargy, social withdrawal, irritability, sleep problems, headaches, and diarrhea.

Behavioral interventions still best

Most early intervention therapies used in treating children with autism spectrum disorders are based on the principles of applied behavioral analysis, which uses positive reinforcement and other techniques to encourage behavior change.

Although the evidence is limited, studies suggest that high-intensity interventions (at least 30 hours a week for one to three years) improve children's language skills, behavior, and thinking ability when compared with other (broadly defined) community treatments. As such, behavioral interventions remain the best choice for treating children with autism spectrum disorders.

McPheeters ML, et al. "A Systematic Review of Medical Treatments for Children with Autism Spectrum Disorders," Pediatrics (May 2011): Vol. 127, No. 5, pp. e1312–21.

Warren Z, et al. "A Systematic Review of Early Intensive Intervention for Autism Spectrum Disorders," Pediatrics (May 2011): Vol. 127, No. 5, pp. e1303–11.

For more references, please see www.health.harvard.edu/mentalextra.

McPheeters ML, et al. "A Systematic Review of Medical Treatments for Children with Autism Spectrum Disorders," Pediatrics (May 2011): Vol. 127, No. 5, pp. e1312–21.

Warren Z, et al. "A Systematic Review of Early Intensive Intervention for Autism Spectrum Disorders," Pediatrics (May 2011): Vol. 127, No. 5, pp. e1303–11.

For more references, please see www.health.harvard.edu/mentalextra.