Antidepressants commonly prescribed to people with autistic spectrum disorders cannot be recommended based on current evidence, a new study by Cochrane Researchers concludes. Despite some evidence of benefits in adults diagnosed with autism, they say there is no evidence for any benefits associated with selective serotonin reuptake inhibitors (SSRIs) in children, who may suffer serious adverse effects as a result of taking the drugs.

Autistic spectrum disorders are difficult to treat because of the range of symptoms experienced by patients, including difficulties with social interactions and communication. SSRIs are among the most commonly prescribed medications, although none have been specifically approved by any drug authority for use in autism. In the UK, most antidepressants are not approved for children for any condition. The rationale behind the use of SSRIs in autism is that they act on serotonin, the same chemical in the body that is responsible for some of the psychological processes affected by the condition.

The researchers included a total of seven trials, involving 271 patients, in their study. The trials evaluated fluoxetine, fluvoxamine, fenfluramine and citalopram. Overall, the researchers found no benefit in the five trials in children and some evidence of serious harm, including one child who suffered a prolonged seizure after taking citalopram. The two trials in adults were very small and thus, although there was some evidence for improvement in symptoms, the authors concluded there was too little evidence for the drugs to be recommended. A major problem with analysing the results was that all the trials used different measures for assessing the drugs' effects.

"We can't recommend SSRIs as treatments for children, or adults, with autism at this time. However, decisions about the use of SSRIs for co-occurring obsessive-compulsive disorder, aggression, anxiety or depression in individuals with autism should be made on a case by case basis," said lead author Katrina Williams of the School of Women's and Children's Health at the University of New South Wales & Sydney Children's Hospital in Sydney, Australia.

"Not all the SSRIs currently in use have undergone controlled trials for autistic spectrum disorders, but parents are often anxious to try treatments regardless of the lack of evidence. It's important that doctors are open about the lack of evidence, and explain any risks fully, before prescribing these treatments."

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More information: Williams K, Wheeler DM, Silove N, Hazell P. Selective serotonin reuptake inhibitors (SSRIs) for autism spectrum disorders (ASD). Cochrane Database of Systematic Reviews 2010, Issue 8. Art. No.: CD004677. Williams K, Wheeler DM, Silove N, Hazell P. Selective serotonin reuptake inhibitors (SSRIs) for autism spectrum disorders (ASD). Cochrane Database of Systematic Reviews 2010, Issue 8. Art. No.: CD004677. DOI: 10.1002/14651858.CD004677.pub2