SRIs may have effect on repetitive behaviors in ASD

Serotonin receptor inhibitors (SRIs) may have a small but significant effect in the treatment of restricted and repetitive behaviors in autism spectrum disorders (ASDs), according to a meta-analysis of randomized, controlled trials, but a definitive answer may be lost to publication bias.

Noting the similarities between repetitive behaviors of ASD and obsessive-compulsive disorder (OCD) along with the efficacy of SRI treatment of OCD as shown in controlled trials, researchers analyzed 6 completed randomized, double-blind, placebo-controlled trials to see what effect SRIs had on restricted and repetitive behavior, a core feature of ASD.

The meta-analysis of 5 published trials and 1 unpublished trial involving 365 participants demonstrated a small effect of SRIs for the treatment of repetitive behaviors in autism, including obsessions and compulsions. However, after using a nonparametric method to account for the role of other unpublished studies, the researchers found that because of publication bias, there was no longer a significant benefit of SRIs for the treatment of repetitive behaviors.

The researchers said they uncovered as many completed SRI trials in ASD with unpublished results as were published. They noted that publication bias has been demonstrated previously to influence the estimates of other interventions in child psychiatry and medicine, particularly the potential efficacy of antidepressant agents, and suggested that without timely, transparent, and complete disclosure of trial results, the efficacy of available medications for patients with ASD will be difficult to determine.

“Identifying effective treatments for these patients will be difficult if partial and selective publication of clinical trials persists, an issue that experts indicate is widespread across all fields of medicine, is not specific to industry or academia (but plagues both), and that may be best addressed with greater enforcement of the registration and reporting of all clinical trials and their results,” they concluded.

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