Teens and children with autism spectrum disorders who were given citalopram, an antidepressant, experienced no change in their repetitive behaviors, according to a study reported in Archives of General Psychiatry. Repetitive behaviors are common among people with autism, as are inflexible routines, which sometimes interfere with everyday life.

Although the FDA (Food and Drug Administration) has not approved any medications to treat the main symptoms of autism and related disorders, drugs such as citalopram are being used to treat patients with autism more and more frequently.

Citalopram is an SSRI (selective serotonin reuptake inhibitor). It alters how the brain regulates serotonin, a neurotransmitter. Lawrence Scahill, Yale University School of Nursing and the Child Study Center, and principal investigator in this new study, said citalopram is becoming an increasingly popular treatment for repetitive behavior among patients with autism because it is prescribed for obsessive-compulsive disorder (among people without autism).

Some studies have indicated that some abnormalities of the serotonin system may be present in people with autism. As SSRIs are effective in treating adults and children with OCD (obsessive-compulsive disorder), Scahill says some health care professionals assumed it could also be adapted for children with autism. Scahill said "Despite the limited evidence supporting their use in children with autism, SSRIs are among the most frequently used medications in this population. This is due in part because of their perceived safety."

Scahill and team, many of whom were from other institutions, carried out a randomized controlled trial to find how safe and effective citalopram was with children with autism spectrum disorders who also had moderate levels of repetitive behavior. The study included 149 children, aged 5 to 17. 73 of them received citalopram, while the other 76 received a placebo (dummy drug) for 12 weeks.

The study revealed that citalopram was no better or worse than the placebo. The scientists did report, though, that those on citalopram had a higher risk of reporting side effects, such as insomnia, impulsiveness, decreased concentration, diarrhea, dry skin, hyperactivity, and stereotypy (abnormal repetitive movements.

Scahill said "These results highlight the importance of placebo-controlled trials of medications commonly used for children with autism spectrum disorders to determine whether risks of medications outweigh benefits."

Fred Volkmar, Yale Child Study Director, who wrote an accompanying commentary, said the results of this study may change the way SSRIs are being prescribed to children with autism. "Previous double-blind, placebo-controlled studies with SSRIs in adults with autism showed a reduction in levels of repetitive behaviors. Given the frequency of such behaviors in children with autism and their association with other features such as anxiety, depression and rigidity, selective serotonin reuptake inhibitors would seem to have, at the least in theory, some therapeutic potential. Although the findings in the study were negative, the results are not difficult to interpret. The medication does not appear to be useful for repetitive behaviors in children with autism and related conditions. We need more studies of this kind to advance research and guide clinical practice."

The study was funded by the National Institutes of Health via STAART center contracts. It was also partly funded by a Clinical and Translational Science Award from the National Center for Research Resources at the National Institutes of Health.

"Lack of Efficacy of Citalopram in Children With Autism Spectrum Disorders and High Levels of Repetitive Behavior. Citalopram Ineffective in Children With Autism."
Bryan H. King, MD; Eric Hollander, MD; Linmarie Sikich, MD; James T. McCracken, MD; Lawrence Scahill, MSN, PhD; Joel D. Bregman, MD; Craig L. Donnelly, MD; Evdokia Anagnostou, MD; Kimberly Dukes, PhD; Lisa Sullivan, PhD; Deborah Hirtz, MD; Ann Wagner, PhD; Louise Ritz, MBA; for the STAART Psychopharmacology Network
Arch Gen Psychiatry. 2009;66(6):583-590. Link to abstract

Commentary
"Citalopram Treatment in Children With Autism Spectrum Disorders and High Levels of Repetitive Behavior."
Fred R. Volkmar, MD
Arch Gen Psychiatry. 2009;66(6):581-582. Link to commentary

Written by Christian Nordqvist