The growing prevalence of autism worldwide has parents and clinicians searching for effective treatment options. Though not approved by the United States Food and Drug Administration for the treatment of autism, a common class of antidepressants is often prescribed to treat the symptoms of autism in children. The selective serotonin reuptake inhibitors (SSRIs) are among the most widely used drugs for autism treatment, even though the effectiveness to date has been questionable. A new study published in the June issue of Archives of General Psychiatry reports that, not only are SSRIs ineffective, they may actually cause unintended side effects.

The study, funded by the National Institutes of Health, evaluated 149 children aged 5 to 17 years who had a diagnosis of autism spectrum disorders, Asperger disorder, or pervasive developmental disorder. The patients also had at least moderate severity ratings according to the Clinical Global Impressions, Severity of Illness Scale, as well as at least moderate compulsive behaviors according to the Children’s Yale-Brown Obsessive Compulsive Scale. The children were randomized to receive either citalopram (Celexa) or placebo by mouth daily for 12 weeks. During the trial period, physicians rated the children’s symptoms on a scale of 1 to 7, with 7 corresponding to more severe or worsening behaviors.

At the conclusion of the trial, nearly one-third (32.9%) of the patients receiving citalopram showed improvement in symptoms, but this was not significantly different from the 34.2% of patients who showed symptom improvement with placebo. Further, patients receiving citalopram were more likely to experience side effects, including nightmares, increased energy level, impulsiveness, decreased concentration, hyperactivity, diarrhea, insomnia, and dry skin than patients receiving placebo. Also, citalopram, as with all SSRIs, carries a warning regarding increased suicidal thoughts and behavior in children and adolescents, though no suicidal ideations were experienced in this study population. Overall, the authors of the current study conclude that citalpram cannot be endorsed as treatment for autism symptoms, since the risks outweigh the benefits.

Abnormal serotonin function is thought to contribute to some of the common symptoms of autism, namely repetitive behaviors such as spinning, twirling, and head-banging. Therefore, SSRIs were a natural choice for treatment of these behaviors. Today, the worldwide market for autism drug treatment is $2 billion and SSRIs account for 60% of that total. However, trials and data concerning the effectiveness of SSRIs in autism are mixed, at best. Some patients do experience symptom improvement, but there are several known risks of SSRI treatment that are particularly concerning in the autism population: suicide risk and increased agitation and aggression, primarily. Also, many of the clinical trials evaluated small populations, and many have used weak study designs, making the conclusions somewhat unreliable.

Treating autism — a condition with an unknown cause and wide-ranging symptoms — remains challenging. Symptom improvement during SSRI treatment may be due to the “placebo effect,” or the random fluctuation of autism symptoms over time. The actual outcomes are uncertain, but many clinicians are beginning to question the benefit of SSRIs versus the risks of treatment. At the very least, the door is still open to investigating the cause and possible treatment options for the ever-prevalent autism and related disorders.

References

Hetrick S, Merry S, McKenzie J, Sindahl P, Proctor M. Selective serotonin reuptake inhibitors (SSRIs) for depressive disorders in children and adolescents. Cochrane Database Syst Rev. 2007(3):CD004851.

King, B., Hollander, E., Sikich, L., McCracken, J., Scahill, L., Bregman, J., Donnelly, C., Anagnostou, E., Dukes, K., Sullivan, L., Hirtz, D., Wagner, A., Ritz, L., & , . (2009). Lack of Efficacy of Citalopram in Children With Autism Spectrum Disorders and High Levels of Repetitive Behavior: Citalopram Ineffective in Children With Autism Archives of General Psychiatry, 66 (6), 583-590 DOI: 10.1001/archgenpsychiatry.2009.30

Kolevzon A, Mathewson KA, Hollander E. Selective serotonin reuptake inhibitors in autism: a review of efficacy and tolerability. J Clin Psychiatry. Mar 2006;67(3):407-414.

SOORYA, L., KIARASHI, J., & HOLLANDER, E. (2008). Psychopharmacologic Interventions for Repetitive Behaviors in Autism Spectrum Disorders Child and Adolescent Psychiatric Clinics of North America, 17 (4), 753-771 DOI: 10.1016/j.chc.2008.06.003