Objective
Autism spectrum disorder (ASD) is characterized by persistent deficits in social communication and social interaction and by restricted and repetitive patterns of behavior. Some studies have shown that substances derived from Cannabis sativa improve the quality of life of children with ASD without causing serious adverse effects, thus providing an alternative therapeutic option. The objective of this study was to evaluate the efficacy and safety of a cannabis extract rich in cannabidiol (CBD) in children with ASD.

Methods
In this randomized, double-blind, placebo-controlled clinical trial, 60 children, aged from 5 to 11 years, were selected and divided into two groups: the treatment group, which received the CBD-rich cannabis extract, and the control group, which received the placebo. They both used their respective products for a period of 12 weeks. Statistical analysis was done by two-factor mixed analysis of variance (two-way ANOVA).

Results
Significant results were found for social interaction (F1,116 = 14.13, p = 0.0002), anxiety (F1,116 = 5.99, p = 0.016), psychomotor agitation (F1,116 = 9.22, p = 0.003), number of meals a day (F1,116 = 4.11, p = 0.04), and concentration (F1,48 = 6.75, p = 0.01), the last of which was only significant in mild ASD cases. Regarding safety, it was found that only three children in the treatment group (9.7%) had adverse effects, namely dizziness, insomnia, colic, and weight gain.

Conclusion
CBD-rich cannabis extract was found to improve one of the diagnostic criteria for ASD (social interaction), as well as features that often co-exist with ASD, and to have few serious adverse effects.