Effect Size of Autism Treatments
At the 2014 meeting of the American Academy of Child and Adolescent Psychiatry, Fung et al. presented a meta-analysis of treatments for autism that ranked them in terms of statistical effect size, ranging from 0.9 (large), to 0.5 to 0.8 (medium), to <0.4 (small). The only drug with a large effect size was risperidone, at 0.9. Most effect sizes were medium, including aripiprazole at 0.8 and N-acetylcysteine (NAC) at 0.7. Both clonidine and methylphenidate had effect sizes of 0.6, and tianeptine’s was 0.5.
Fung and colleagues noted that the first two on the list, the atypical antipsychotics risperidone and aripiprazole, often have problematic side effects (such as sedation, weight gain, and motor symptoms) that must be balanced against their effectiveness. In contrast, NAC is well tolerated with few side effects, and two placebo controlled studies showed that it was effective both alone and as an adjunctive treatment to the antipsychotic risperidone.
