First randomized trial of cannabinoids for ADHD found trends toward improvement in hyperactivity and impulsivity
A pilot RCT of Sativex (THC:CBD spray) in 30 adults with ADHD found no significant improvement on the primary outcome but nominally significant improvements in hyperactivity/impulsivity and cognitive inhibition, providing the first experimental evidence for the self-medication theory.
Quick Facts
What This Study Found
In this pilot randomized, placebo-controlled trial, 30 adults with ADHD received either Sativex oromucosal spray (THC:CBD) or placebo. The primary outcome, cognitive performance and activity level measured by the QbTest, showed no significant difference, though active group scores were consistently better than placebo.
Secondary outcomes were more encouraging: Sativex was associated with nominally significant improvement in hyperactivity/impulsivity (p=0.03) and a cognitive measure of inhibition (p=0.05). Trends toward improvement were seen for inattention (p=0.10) and emotional lability (p=0.11). Per-protocol effects (excluding dropouts) were stronger.
However, results did not survive adjustment for multiple testing. One serious adverse event (muscular seizures/spasms) occurred in the active group.
Key Numbers
30 participants (15 active, 15 placebo). Hyperactivity/impulsivity: p=0.03. Cognitive inhibition: p=0.05. Inattention: p=0.10. Emotional lability: p=0.11. None significant after multiple testing correction. 1 serious adverse event (muscular seizures) in active group.
How They Did This
Pilot randomized, double-blind, placebo-controlled trial (EMA-C trial). 30 adults with ADHD were randomized 1:1 to Sativex or placebo. Primary outcome: QbTest (computerized attention and activity measure). Secondary outcomes: ADHD symptom ratings and emotional lability. Recruitment: July 2014 to June 2015.
Why This Research Matters
Adults with ADHD frequently report self-medicating with cannabis, and some US psychiatrists prescribe it despite no prior controlled evidence. This is the first RCT to test cannabinoids for ADHD, and while not definitive, it provides preliminary experimental support for the self-medication theory by showing trends toward symptom improvement.
The Bigger Picture
The relationship between cannabis and ADHD is complex. Cannabis acutely impairs attention and memory in most people, but adults with ADHD often report the opposite, that cannabis helps them focus. This trial suggests there may be a biological basis for this paradoxical response, though much larger trials are needed to confirm it.
What This Study Doesn't Tell Us
Very small pilot study (n=30) underpowered to detect modest effects. Primary outcome was not significant. Secondary outcome significance did not survive multiple testing correction. One serious adverse event. Short duration. Does not address long-term efficacy or cognitive effects of sustained use.
Questions This Raises
- ?Would a larger trial confirm the trends seen here?
- ?Do specific cannabinoid ratios (higher CBD, different THC:CBD ratios) work better for ADHD?
- ?Are there ADHD subtypes that respond better to cannabinoids?
- ?How do cannabinoid effects on ADHD compare to standard medications?
Trust & Context
- Key Stat:
- Hyperactivity/impulsivity improved (p=0.03) but did not survive multiple testing correction
- Evidence Grade:
- Pilot RCT with placebo control and blinding. Proper design but too small to be definitive. Results are hypothesis-generating rather than conclusive.
- Study Age:
- Published in 2017. This remains one of the only RCTs of cannabinoids for ADHD. Larger trials are needed.
- Original Title:
- Cannabinoids in attention-deficit/hyperactivity disorder: A randomised-controlled trial.
- Published In:
- European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, 27(8), 795-808 (2017)
- Authors:
- Cooper, Ruth E, Williams, Emma, Seegobin, Seth, Tye, Charlotte, Kuntsi, Jonna, Asherson, Philip
- Database ID:
- RTHC-01360
Evidence Hierarchy
Participants are randomly assigned to treatment or placebo groups to test cause and effect.
What do these levels mean? →Frequently Asked Questions
Does cannabis help ADHD?
This small pilot study found trends toward improvement in hyperactivity, impulsivity, and cognitive inhibition, but the results were not statistically robust after accounting for multiple comparisons. It provides preliminary evidence supporting the self-medication reports from ADHD patients but does not prove effectiveness.
Should people with ADHD use cannabis instead of their medication?
This study does not support replacing ADHD medication with cannabis. It was a 30-person pilot study with results that did not reach definitive significance. Standard ADHD medications have far more evidence supporting their effectiveness. The study's main contribution is suggesting that larger trials are warranted.
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Cite This Study
https://rethinkthc.com/research/RTHC-01360APA
Cooper, Ruth E; Williams, Emma; Seegobin, Seth; Tye, Charlotte; Kuntsi, Jonna; Asherson, Philip. (2017). Cannabinoids in attention-deficit/hyperactivity disorder: A randomised-controlled trial.. European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, 27(8), 795-808. https://doi.org/10.1016/j.euroneuro.2017.05.005
MLA
Cooper, Ruth E, et al. "Cannabinoids in attention-deficit/hyperactivity disorder: A randomised-controlled trial.." European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, 2017. https://doi.org/10.1016/j.euroneuro.2017.05.005
RethinkTHC
RethinkTHC Research Database. "Cannabinoids in attention-deficit/hyperactivity disorder: A ..." RTHC-01360. Retrieved from https://rethinkthc.com/research/cooper-2017-cannabinoids-in-attentiondeficithyperactivity-disorder
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.