Systematic review found cannabis may help reduce several autism-related symptoms | Research

The takeaway

A systematic review of 9 studies found cannabis products reduced hyperactivity, self-mutilation, anxiety, sleep problems, and irritability in people with autism, while improving cognition and social interaction.

Families affected by autism exploring treatment options, and clinicians considering cannabinoid therapies for ASD.

Improvements reported across multiple symptom domains in all 9 studies

What the researchers found

Across 9 studies, cannabis products reduced the number or intensity of multiple ASD symptoms including hyperactivity, self-mutilation, anger, sleep problems, anxiety, irritability, and depression. Improvements were also reported in cognition, sensory sensitivity, attention, social interaction, and language.

Why it matters

Autism spectrum disorder has limited effective treatments for many of its associated symptoms. This review consolidates the growing evidence that cannabis-based products may offer relief for some of the most challenging aspects of ASD.

The numbers in context

9 studies included. Improvements reported across multiple symptom domains. Most common adverse effects were sleep disorders, restlessness, nervousness, and appetite changes.

How the study worked

Systematic review following PRISMA guidelines, searching MEDLINE/PubMed, SciELO, Scopus, and Web of Science with no language limits. Nine studies were selected and analyzed.

What this study cannot tell us

Only 9 studies met inclusion criteria. Most were observational with small samples. Different cannabis products, doses, and formulations were used across studies, making direct comparison difficult.

How to read the evidence

Moderate: systematic review methodology, but limited by small number of mostly observational studies.

When this study was published

Published in 2022.

The bigger picture

While these results are promising, the review emphasizes that most studies were observational or open-label, and randomized controlled trials are needed before cannabis can be recommended as a standard treatment for ASD symptoms.

Questions still open

Which specific cannabinoid ratios are most effective for different ASD symptoms? Are the benefits sustained long-term? Do children and adults with ASD respond differently to cannabis treatment?

Common questions

What symptoms improved most?

Studies reported improvements in hyperactivity, self-mutilation, anger episodes, sleep problems, anxiety, restlessness, irritability, aggressiveness, and depression. Cognitive, sensory, and social improvements were also noted.

Were there side effects?

Yes. The most common adverse effects were sleep disorders, restlessness, nervousness, and changes in appetite.

Is cannabis recommended for autism based on this review?

Not yet. The authors conclude cannabis has promising effects but emphasize that randomized, placebo-controlled trials are needed before it can be recommended as a standard treatment.

Read the original research

Cannabis and cannabinoid use in autism spectrum disorder: a systematic review.

Trends in psychiatry and psychotherapy, 44, e20200149

View on PubMed ↗Publisher’s paper ↗

Citation

Silva, Estácio Amaro da; Medeiros, Wandersonia Moreira Brito; Torro, Nelson; Sousa, João Marçal Medeiros de; Almeida, Igor Bronzeado Cahino Moura de; Costa, Filipe Barbosa da; Pontes, Katiúscia Moreira; Nunes, Eliane Lima Guerra; Rosa, Marine Diniz da; Albuquerque, Katy Lísias Gondim Dias de. (2022). Cannabis and cannabinoid use in autism spectrum disorder: a systematic review.. Trends in psychiatry and psychotherapy, 44, e20200149. https://doi.org/10.47626/2237-6089-2020-0149