Of 1,301 papers screened, only 27 met inclusion criteria for CBD in psychiatric disorders, with the strongest signals for substance use disorders, chronic psychosis, and anxiety, though the evidence remains insufficient for clinical recommendations.
Psychiatrists, patients considering CBD for mental health, and regulatory bodies evaluating CBD health claims.
Only 27 qualifying studies
What the researchers found
From 1,301 screened papers, 27 met inclusion criteria (RCTs of CBD for psychiatric disorders). Limited evidence suggested potential therapeutic effects for substance use disorders, chronic psychosis, and anxiety. Evidence was insufficient for depression, PTSD, sleep, cognitive impairment, eating disorders, and other conditions.
Why it matters
With CBD products increasingly marketed for mental health conditions, this systematic review provides a reality check: while some conditions show promise, the clinical trial base is tiny relative to the scale of CBD use for psychiatric symptoms.
The numbers in context
1,301 papers identified. 190 after abstract screening. 27 met inclusion criteria. Most promising: substance use disorders, chronic psychosis, anxiety. Insufficient evidence for depression, PTSD, sleep, cognition, eating disorders.
How the study worked
Systematic review following PRISMA guidelines, searching for RCTs of CBD for psychiatric conditions including substance use, psychosis, anxiety, mood, cognitive, sleep, personality, eating, OCD, PTSD, and somatic disorders.
What this study cannot tell us
Very few RCTs available. Heterogeneous CBD formulations and doses across studies. Most studies had small sample sizes. The systematic review could only assess what has been studied, leaving many conditions essentially unexamined.
How to read the evidence
Rated preliminary because despite rigorous systematic review methodology, the underlying evidence base is extremely limited.
When this study was published
Published in 2019. Additional CBD clinical trials have been conducted since.
The bigger picture
The contrast between 27 qualifying studies and millions of people using CBD for mental health highlights an enormous evidence-practice gap. The conditions where CBD shows the most promise (psychosis, substance use) are not the ones most consumers are targeting (anxiety, sleep, mood).
Questions still open
- Will larger RCTs confirm the signals for psychosis and substance use disorders? Does CBD have any role in the conditions where evidence is currently lacking? Could the absence of evidence reflect lack of study rather than lack of efficacy?
Common questions
Does CBD help with psychiatric conditions?
What about CBD for depression or sleep?
Read the original research
Cannabidiol (CBD) use in psychiatric disorders: A systematic review.
Neurotoxicology, 74, 282-298
Citation
Bonaccorso, Stefania; Ricciardi, Angelo; Zangani, Caroline; Chiappini, Stefania; Schifano, Fabrizio. (2019). Cannabidiol (CBD) use in psychiatric disorders: A systematic review.. Neurotoxicology, 74, 282-298. https://doi.org/10.1016/j.neuro.2019.08.002
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