Antidepressants should not be prescribed to people with autism, researchers have said.
The most commonly used type of antidepressants are SSRIs (selective serotonin re-uptake inhibitors). SSRIs work on the serotonin levels in the brain. Serotonin is a neurotransmitter which passes messages between nerve cells. SSRIs help the serotonin to function properly, thereby alleviating depression.
According to a team of Cochrane researchers based in Australia, autism is difficult to treat because of the range of symptoms experienced by patients.
Autism, also known as autism spectrum disorder (ASD), is a biological disorder of the brain that impairs communication and social skills. Signs can include an absence of eye contact, apparent aloofness, avoidance of physical contact even with family, a difficulty dealing with interruptions to routine and a lack of interest in other people and what they are doing.
The researchers noted that SSRIs are sometimes prescribed to people with autism even though none of these drugs have been specifically approved by any drug authority for use in people with the 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 analysed seven trials involving 271 patients. Five of these trials involved children and a number of antidepressants were evaluated.
The team found no benefit in the five trials involving children. In fact, they found some evidence of serious harm, including one child who suffered a prolonged seizure after taking an SSRI.
The two trials in adults were very small, therefore while there was some evidence of an improvement in symptoms, the researchers concluded that there was too little evidence for the drugs to be recommended.
"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 (OCD), aggression, anxiety or depression in individuals with autism should be made on a case by case basis," said lead author, Dr Katrina Williams of Sydney Children's Hospital.
She pointed out that while some SSRIs currently in use have not undergone controlled trials for autism, ‘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," she said.
Details of these findings are published in the Cochrane Database of Systematic Reviews 2010.
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