Cannabinoids as alleviating treatment for core symptoms of autism spectrum disorder in children and adolescents: a systematic review.

Introduction: Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder affecting about 1% of children. The disorder is characterized by difficulties within three core symptoms: social interactions, communication, and restricted or repetitive behavior. There is currently no approved psychopharmacological treatment; however, it is hypothesized that ASD symptoms might be ameliorated by manipulating the endocannabinoid (eCB) system.This study aims to review the existing research on cannabinoids as a potential effective treatment for the core symptoms of ASD in children and adolescents. Methods: A literature search was conducted on PubMed, Embase, APA PsychInfo, and Cochrane. The available literature was screened, and studies were included if: the study population consisted of children/adolescents, the treatment involved cannabinoids, and the outcome assessed was the impact on core ASD symptoms. Results: The search yielded five studies, two RCTs and three cohort studies. All the included studies reported an effect of the cannabinoid treatment; however, most of these effects were non-significant and not related to core symptoms. Only one study found a significant improvement on all three core symptoms. The risk of bias was rated as "high" or "very high" in four studies and as "low" in one study. Discussion: Although the included studies did not find substantial results regarding core ASD symptoms, they all reported that cannabinoid treatment had other positive effects. However, Long term outcome is unknown, and safety aspects are scarcely discussed. Conclusion: Based on this review, the effect of cannabinoid treatment on ASD core symptoms is not clear; therefore, further studies are required.