Is there a role for cannabidiol in psychiatry?

Abstract

Objectives: Understanding whether cannabidiol (CBD) is useful and safe for the treatment of psychiatric disorders is essential to empower psychiatrists and patients to take good clinical decisions. Our aim was to conduct a systematic review regarding the benefits and adverse events (AEs) of CBD in the treatment of schizophrenia, psychotic disorders, anxiety disorders, depression, bipolar disorder and substance-use disorders.

Methods: We conducted a literature search in PubMed, Scielo, and Clinicaltrials.gov databases. Evidence was classified according to the WFSBP task forces standards.

Results: Bibliographic research yielded 692 records. After analysis, we included six case reports and seven trials, comprising 201 subjects. Most the studies published presented several drawbacks and did not reach statistical significance. We have not found evidence regarding major depressive and bipolar disorders. The level of evidence for cannabis withdrawal is B; cannabis addiction is C2; treatment of positive symptoms in schizophrenia and anxiety in social anxiety disorder is C1. Discrete or no AEs were reported. The most frequently reported AEs are sedation and dizziness.

Conclusions: The evidence regarding efficacy and safety of CBD in psychiatry is still scarce. Further larger well-designed randomised controlled trials are required to assess the effects of CBD in psychiatric disorders.

Keywords:

• Cannabidiol
• pharmacotherapy
• psychiatry
• adverse effects
• psychiatric disorders

Acknowledgements

This study was made possible by the International Network of Research of Restricted or Prohibited Substances by Government Agencies.

Disclosure statement

F.D.G received CME grants, received paid speakership from Janssen and Pfizer; received research grants from Fundação de Amparo à Pesquisa do Estado de Minas Gerais, Brazil) and National Council for Scientific and Technological Development, CNPq (Conselho Nacional de Desenvolvimento Tecnológico, Brazil).

The other authors have no conflicts to declare.

Additional information

Funding

This study was partially supported by FAPEMIG (Fundação de Amparo à Pesquisa do Estado de Minas Gerais, Brazil) [grant APQ-01714-13] and National Council for Scientific and Technological Development, CNPq (Conselho Nacional de Desenvolvimento Tecnológico, Brazil) [grant 486221/2013-0]. The funders did not interfere with any procedure regarding the production of this paper.