How effective and safe is medical cannabis as a treatment of mental disorders? A systematic review.

[Correction Notice: An Erratum for this article was reported in Vol 269(8) of European Archives of Psychiatry and Clinical Neuroscience (see record [rid]2019-19802-001[/rid]). The article was originally published Online First without open access. After publication in volume 269, issue 1, page 87–105 the author decided to opt for Open Choice and to make the article an Open Access publication. Therefore, the copyright of the article has been changed to © The Author(s) 2019 and the article is forthwith distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, duplication, adaptation, distribution and reproduction in any medium or format, as long as one gives appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made. The original article has been corrected.] We conducted a review of systematic reviews (SRs) and randomized-controlled trials (RCTs) to analyze efficacy and safety of cannabis-based medication in patients with mental disorders. Five data bases were systematically searched (2006—August 2018); 4 SRs (of 11 RCTs) and 14 RCTs (1629 participants) were included. Diagnoses were: dementia, cannabis and opioid dependence, psychoses/schizophrenia, general social anxiety, posttraumatic stress disorder, anorexia nervosa, attention-deficit hyperactivity disorder, and Tourette`s disorder. Outcome variables were too heterogeneous to conduct a meta-analysis. A narrative synthesis method was applied. The study quality was assessed using the risk-of-bias tool and SIGN-checklists. THC- and CBD-based medicines, given as adjunct to pharmaco- and psychotherapy, were associated with improvements of several symptoms of mental disorders, but not with remission. Side effects occurred, but severe adverse effects were mentioned in single cases only. In order to provide reliable treatment recommendations, more and larger RCTs with follow-up assessments, consistent outcome measures and active comparisons are needed. (PsycInfo Database Record (c) 2021 APA, all rights reserved)