First human lab study tested cannabinoids for OCD symptoms

In a small pilot RCT, smoked cannabis (high THC or high CBD) did not significantly reduce OCD symptoms compared to placebo in a controlled lab setting, though the study was underpowered.

Kayser, Reilly R et al.·Depression and anxiety·2020·Preliminary EvidenceRandomized Controlled Trial
RTHC-02644Randomized Controlled TrialPreliminary Evidence2020RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Randomized Controlled Trial
Evidence
Preliminary Evidence
Sample
N=14

What This Study Found

Fourteen adults with OCD underwent symptom provocation after smoking cannabis with high THC, high CBD, or placebo in a crossover design. Neither active condition significantly reduced obsessions or compulsions compared to placebo, though there were trends toward reduced anxiety with CBD.

Key Numbers

14 participants; three conditions (high THC, high CBD, placebo) in crossover design; no statistically significant reduction in OCD symptoms with either active condition.

How They Did This

Double-blind, placebo-controlled, within-subjects crossover design. 14 adults with OCD smoked cannabis (high THC, high CBD, or placebo) before a symptom provocation task. OCD symptoms, anxiety, and distress were measured.

Why This Research Matters

Despite widespread anecdotal claims about cannabis helping OCD, this is one of the first controlled human lab studies to test it. The null findings are important for tempering expectations, though the small sample limits conclusions.

The Bigger Picture

Anecdotal reports of cannabis helping OCD symptoms are common, but controlled research tells a more nuanced story. This pilot suggests that acute cannabinoid exposure may not directly reduce core OCD symptoms, though larger studies are needed.

What This Study Doesn't Tell Us

Very small sample (n=14); acute dosing only (one-time exposure cannot capture effects of sustained use); smoked cannabis makes precise dosing difficult; crossover design may have carryover effects.

Questions This Raises

  • ?Would longer-term CBD treatment show different results?
  • ?Could specific cannabinoid doses or ratios be more effective for OCD?

Trust & Context

Key Stat:
Neither THC nor CBD significantly reduced OCD symptoms vs. placebo
Evidence Grade:
Preliminary: very small sample (n=14), acute dosing only, pilot study.
Study Age:
Published 2020.
Original Title:
Acute effects of cannabinoids on symptoms of obsessive-compulsive disorder: A human laboratory study.
Published In:
Depression and anxiety, 37(8), 801-811 (2020)
Database ID:
RTHC-02644

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled TrialGold standard for testing treatments
This study
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal Study

Participants are randomly assigned to treatment or placebo groups to test cause and effect.

What do these levels mean? →

Frequently Asked Questions

Did cannabis help OCD symptoms at all?

Neither high-THC nor high-CBD cannabis significantly reduced OCD symptoms compared to placebo. There was a non-significant trend toward reduced anxiety with CBD.

Why is this study important despite null results?

It is one of the first controlled human experiments testing cannabinoids for OCD. Null findings from rigorous studies are important for balancing anecdotal claims.

Read More on RethinkTHC

Cite This Study

RTHC-02644·https://rethinkthc.com/research/RTHC-02644

APA

Kayser, Reilly R; Haney, Margaret; Raskin, Marissa; Arout, Caroline; Simpson, Helen Blair. (2020). Acute effects of cannabinoids on symptoms of obsessive-compulsive disorder: A human laboratory study.. Depression and anxiety, 37(8), 801-811. https://doi.org/10.1002/da.23032

MLA

Kayser, Reilly R, et al. "Acute effects of cannabinoids on symptoms of obsessive-compulsive disorder: A human laboratory study.." Depression and anxiety, 2020. https://doi.org/10.1002/da.23032

RethinkTHC

RethinkTHC Research Database. "Acute effects of cannabinoids on symptoms of obsessive-compu..." RTHC-02644. Retrieved from https://rethinkthc.com/research/kayser-2020-acute-effects-of-cannabinoids

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.