An antidepressant widely used to treat autism in children not only does not work but does more harm than good, according to a study.
It has found that Celexa has no beneficial effects, and actually causes repetitive behaviour, hyperactivity, nightmares and other sleep problems.
The research was conducted by Dr Bryan King, director of child and adolescent psychiatry at Seattle Children's Hospital and the University of Washington medical school.
Celexa belongs to a class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs), which are included among the most widely used medicines used to treat autism.
While the drug is not actually approved for treating the condition, similar antidepressants are prescribed for people with obsessive-compulsive disorder.
That may now change, according to Yale University autism researcher Dr Fred Volkmar, who is commenting in an editorial released with the study and reported in the June issue of Archives of General Psychiatry.
The Celexa results reflect a separate study, which showed that Prozac, another SSRI, also does not reduce repetitive behaviour in people suffering from autism.