CBD may reduce psychotic symptoms from THC and in schizophrenia, but evidence for treating cannabis use disorder is mixed | Research

The takeaway

Clinical evidence suggests CBD can attenuate THC-induced psychotic symptoms and positive symptoms of schizophrenia, but findings on CBD for cannabis use disorder remain inconclusive.

People interested in CBD's psychiatric applications, mental health researchers, those concerned about cannabis-related psychosis

10 clinical studies support CBD's potential to reduce psychotic symptoms

What the researchers found

Across 10 clinical studies, CBD appeared to reduce psychotic-like symptoms triggered by THC in healthy volunteers and positive symptoms in people with schizophrenia. However, results for CBD as a treatment for cannabis use disorder were mixed.

Why it matters

If CBD can counteract THC-related psychosis while also having antipsychotic properties, it could represent a novel treatment approach that targets both substance use and psychotic disorders simultaneously.

The numbers in context

10 clinical studies included; CBD evaluated for three indications: THC-induced psychotic symptoms, schizophrenia, and cannabis use disorders

How the study worked

Narrative review searching PubMed, Cochrane Library, and ClinicalTrials.gov for clinical studies evaluating CBD for THC-induced psychosis, schizophrenia, and cannabis use disorders. Ten studies met inclusion criteria.

What this study cannot tell us

Only 10 studies available, most with small sample sizes. No study examined co-occurring psychotic and cannabis use disorders together. The review is narrative rather than systematic.

How to read the evidence

Narrative review of a limited number of clinical studies with small sample sizes

When this study was published

Published in 2021. Several ongoing clinical trials may provide stronger evidence for CBD's antipsychotic properties.

The bigger picture

The different pharmacological effects of THC and CBD continue to challenge simplistic views of cannabis. The possibility that one component of the plant could treat harm caused by another component has significant implications for both psychiatric treatment and cannabis regulation.

Questions still open

What CBD doses are needed to reliably attenuate psychotic symptoms? Could CBD be used as an adjunct to standard antipsychotic medications? Why are results for cannabis use disorder more mixed than for psychotic symptoms?

Common questions

Can CBD reduce psychotic symptoms from THC?

Clinical evidence suggests yes. Across multiple studies, CBD appeared to attenuate psychotic-like symptoms triggered by THC in healthy volunteers.

Could CBD help treat schizophrenia?

Early clinical evidence suggests CBD may reduce positive symptoms of schizophrenia. However, studies have been small and more research is needed to confirm these findings and determine optimal dosing.

Read the original research

Efficacy of Cannabidiol for Δ-9-Tetrahydrocannabinol-Induced Psychotic Symptoms, Schizophrenia, and Cannabis Use Disorders: A Narrative Review.

Journal of clinical medicine, 10(6)

View on PubMed ↗Publisher’s paper ↗

Citation

Bartoli, Francesco; Riboldi, Ilaria; Bachi, Bianca; Calabrese, Angela; Moretti, Federico; Crocamo, Cristina; Carrà, Giuseppe. (2021). Efficacy of Cannabidiol for Δ-9-Tetrahydrocannabinol-Induced Psychotic Symptoms, Schizophrenia, and Cannabis Use Disorders: A Narrative Review.. Journal of clinical medicine, 10(6). https://doi.org/10.3390/jcm10061303