84% of autism patients reported improvement after six months of CBD-rich cannabis treatment
In a prospective study of 188 autism patients treated with CBD-rich cannabis oil (30% CBD, 1.5% THC) for six months, 83.8% reported improvement, with 30.1% reporting significant improvement and only 25.2% experiencing any side effects.
Quick Facts
What This Study Found
After six months of treatment with cannabis oil (30% CBD, 1.5% THC), 82.4% of 188 ASD patients were still in active treatment. Of 93 patients assessed: 30.1% reported significant improvement, 53.7% moderate improvement, 6.4% slight improvement, and only 8.6% had no change. The most common side effect was restlessness (6.6%). No patients reported worsening.
Key Numbers
188 ASD patients. 82.4% (155) still in active treatment at 6 months. 93 patients assessed: significant improvement 30.1%, moderate 53.7%, slight 6.4%, no change 8.6%. Side effects in 25.2%: restlessness 6.6% most common. Cannabis oil: 30% CBD, 1.5% THC.
How They Did This
Prospective observational study analyzing data collected as part of a treatment program for 188 ASD patients receiving medical cannabis between 2015-2017 in Israel. Treatment primarily used cannabis oil with 30% CBD and 1.5% THC. Outcomes assessed via structured questionnaires at 6 months.
Why This Research Matters
This is one of the largest prospective studies of medical cannabis for autism, with 6-month follow-up data. The high continuation rate (82.4%) and broad improvement (83.8% of assessed patients) suggest the treatment is both tolerable and perceived as beneficial.
The Bigger Picture
The autism-cannabis evidence base is growing rapidly, driven by strong parental demand and anecdotal reports. This study, from the group of Raphael Mechoulam (who first isolated THC), adds structured prospective data to what was previously almost entirely anecdotal evidence.
What This Study Doesn't Tell Us
No control group or blinding. Caregiver-reported outcomes are subjective. The 17.6% who discontinued and the additional patients not assessed at 6 months may have had different outcomes. Selection bias: patients who seek cannabis treatment may be predisposed to report benefit.
Questions This Raises
- ?Will randomized controlled trials confirm these results?
- ?Which specific ASD symptoms respond best to CBD-rich cannabis?
- ?What is the optimal CBD:THC ratio and dosing schedule for this population?
Trust & Context
- Key Stat:
- 84% reported improvement
- Evidence Grade:
- Rated moderate because this is a relatively large prospective study with structured data collection, though the lack of a control group limits causal inference.
- Study Age:
- Published in 2019. Co-authored by Raphael Mechoulam, who first synthesized THC. Additional controlled trials of cannabis for ASD have been initiated since.
- Original Title:
- Real life Experience of Medical Cannabis Treatment in Autism: Analysis of Safety and Efficacy.
- Published In:
- Scientific reports, 9(1), 200 (2019)
- Authors:
- Bar-Lev Schleider, Lihi(7), Mechoulam, Raphael(12), Saban, Naama(2), Meiri, Gal, Novack, Victor
- Database ID:
- RTHC-01933
Evidence Hierarchy
Enrolls participants and follows them forward in time.
What do these levels mean? →Frequently Asked Questions
Does cannabis help autism symptoms?
In this study, 84% of assessed patients reported some improvement after six months of CBD-rich cannabis oil. However, without a control group, the contribution of placebo effect cannot be determined.
What formulation was used?
Cannabis oil containing 30% CBD and 1.5% THC. This high CBD-to-THC ratio was chosen to minimize psychoactive effects while maximizing potential therapeutic benefit.
Were there safety concerns?
Side effects were generally mild, with restlessness being most common at 6.6%. Only 25.2% experienced any side effects. No patients reported worsening of their condition.
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Cite This Study
https://rethinkthc.com/research/RTHC-01933APA
Bar-Lev Schleider, Lihi; Mechoulam, Raphael; Saban, Naama; Meiri, Gal; Novack, Victor. (2019). Real life Experience of Medical Cannabis Treatment in Autism: Analysis of Safety and Efficacy.. Scientific reports, 9(1), 200. https://doi.org/10.1038/s41598-018-37570-y
MLA
Bar-Lev Schleider, Lihi, et al. "Real life Experience of Medical Cannabis Treatment in Autism: Analysis of Safety and Efficacy.." Scientific reports, 2019. https://doi.org/10.1038/s41598-018-37570-y
RethinkTHC
RethinkTHC Research Database. "Real life Experience of Medical Cannabis Treatment in Autism..." RTHC-01933. Retrieved from https://rethinkthc.com/research/bar-lev-2019-real-life-experience-of
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.