Abstract
Autism spectrum disorders are characterized by some difficulties with social interactions and communication, atypical patterns of behavior, and unusual reactions to emotions. Studies have found promising results regarding the effects of cannabis on autism. We conducted a systematic review of randomized clinical trials on the effects of cannabis derivatives and their analogs for autism. This review was developed according to the Cochrane Handbook for Systematic Reviews of Interventions and reported according to PRISMA 2020. The protocol was prospectively published in the PROSPERO database (CRD42023468300). We included randomized controlled trials with autism-diagnosed participants treated with any cannabis derivate or its analogs for therapeutic purposes. Two reviewers assessed titles and abstracts independently and potentially eligible full texts were assessed to confirm eligibility. After that, they extracted data using a standardized worksheet. Searches retrieved 1264 references, only 11 RCTs were included, four with available results for children/adolescents with autism. Five different cannabis presentations were tested. One trial pointed that cannabis may improve global assessment symptoms, but for other outcomes results were uncertain. No included study assessed quality of life. The certainty of evidence ranged from very low to low certainty for the assessed outcomes. Cannabis whole plant extract may improve global assessment symptoms, but the different cannabis presentations, outcome assessments and very low certainty of evidence from the included studies make it difficult to draw conclusions about cannabis for people with autism. This scenario of uncertainties impacts directly clinical practice and decision making.