What does the research actually say about cannabis for autism? | Research

The takeaway

Evidence for cannabis as an autism treatment is extremely thin, with only five small studies and mixed results for most symptoms except epilepsy.

Parents and caregivers of children with ASD, clinicians evaluating cannabis-based treatment requests, and researchers studying cannabinoid therapeutics.

Only 5 small studies

What the researchers found

Only five small studies have specifically examined cannabis use in autism spectrum disorders. Results were mixed and inconclusive for most conditions, with epilepsy being the sole exception showing clearer benefit.

Why it matters

Families of children with ASD are increasingly turning to cannabis despite a near-total absence of rigorous evidence. Three large clinical trials were underway at the time of this review, but conclusions remained far ahead of the data.

The numbers in context

Only 5 small studies specifically examined cannabis in ASD. 3 large-scale clinical trials were in progress. Adverse outcomes reported included severe psychosis, increased agitation, somnolence, decreased appetite, and irritability.

How the study worked

Literature review analyzing peer-reviewed studies on cannabis use in ASD populations, including systematic reviews, reports, and experimental studies.

What this study cannot tell us

The review identified very few ASD-specific cannabis studies, so it relied heavily on extrapolating from research on shared symptoms like anxiety and sleep disorders. The wide range of cannabis compositions and dosages across studies limits generalizability.

How to read the evidence

Rated preliminary because the review found extremely limited direct evidence for cannabis in ASD, with most findings extrapolated from other conditions.

When this study was published

Published in 2019. Several large clinical trials referenced were still in progress and may have since reported results.

The bigger picture

The gap between anecdotal enthusiasm and clinical evidence for cannabis in autism is wider than in almost any other condition. This review highlights just how little controlled research exists to guide families making real-time treatment decisions.

Questions still open

Will the three large-scale trials produce clearer answers? How much of the reported benefit is driven by specific cannabinoids versus entourage effects? What are the long-term risks of cannabis use in developing brains of children with ASD?

Common questions

Does cannabis help with autism symptoms?

As of this review, the evidence is extremely limited. Only five small studies had examined cannabis specifically in autism, and results were mixed for everything except epilepsy.

Were there any risks found?

Yes. Adverse outcomes reported in the literature included severe psychosis, increased agitation, somnolence, decreased appetite, and irritability.

What about CBD specifically for autism?

The review did not find strong evidence distinguishing CBD from other cannabinoids for ASD. The overall evidence base was too small to draw firm conclusions about any specific compound.

Read the original research

Current state of evidence of cannabis utilization for treatment of autism spectrum disorders.

BMC psychiatry, 19(1), 328

View on PubMed ↗Publisher’s paper ↗

Citation

Agarwal, Rumi; Burke, Shanna L; Maddux, Marlaina. (2019). Current state of evidence of cannabis utilization for treatment of autism spectrum disorders.. BMC psychiatry, 19(1), 328. https://doi.org/10.1186/s12888-019-2259-4