The differential effects of medicinal cannabis on mental health: A systematic review.
de Bode et al.·Clinical psychology reviewImpact 8.5
MixedGRADEHigh9 citations
Samplek = 49 Studien
Durationunclear
ControlControl conditions
EndpointMental symptoms
Blindingunklar
DesignSystematic Review
”Key finding
CBD showed short-term anxiety relief, CBD+THC helped with withdrawal symptoms and sleep, but THC was associated with dose-dependent side effects and in some cases worsening of primary outcomes; no long-term effects found.
Summary
Systematic review on medical cannabis in mental disorders; k=49 controlled studies from 15 countries (18.341 screened, search October 2023/July 2024). Autism spectrum disorder included as one of 11 evaluated diagnoses. Product composition variable (THC, CBD, THC+CBD combinations); high CBD doses showed acute anxiety reduction, CBD+THC combinations improved sleep and cannabis withdrawal symptoms. THC dose-dependently associated with adverse events, in some cases worsening of primary outcomes (e.g. psychosis). No study found long-lasting medical effects. High risk of bias prevalent. Conclusion: short-term symptom relief possible, but no cure and not without risks for mental health.
P
PopulationAdults with mental disorders (anxiety disorders, tic disorders, ASD, ADHD, OCD, anorexia nervosa, schizophrenia, psychosis, substance use disorders, insomnia, bipolar disorders) in clinical or naturalistic settings
I
InterventionMedical cannabis (THC, CBD, THC+CBD combinations or derivatives, various dosages and applications)
C
ControlControl conditions (controlled studies)
O
OutcomeHigh-dose CBD showed acute anxiety reduction; CBD+THC combinations improved sleep and reduced withdrawal symptoms in cannabis use disorder; THC was associated with dose-dependent adverse effects and in some cases worsening (e.g. psychosis); no study showed sustained effects
Confidence in the evidence
Very lowLowModerateHigh
High
The highest of four GRADE levels, the effect estimate is very reliable.
The use of medicinal cannabis to improve mental health is increasing globally, both in clinical settings and through self-medication. This involves a variety of products containing ∆9-tetrahydrocannabinol (THC), cannabidiol (CBD), THC + CBD combinations, or derivatives. This review provides an up-to-date overview of the positive and negative effects of medicinal cannabis on mental health diagnoses and related symptoms of the Diagnostic and Statistical Manual of Mental Disorders 5th Edition. Searches in PubMed, PsycInfo, Embase, and the Cochrane Library (October 2023 and July 2024) identified 18,341 studies, of which 49 controlled studies from 15 different countries were included. All studies focused on treatment-seeking participants using medicinal cannabis for (symptoms of) their mental health diagnosis. Included diagnoses were anxiety disorders, tic disorders, autism spectrum disorder, attention-deficit hyperactivity disorder, obsessive-compulsive disorders, anorexia nervosa, schizophrenia, psychosis, substance use disorders, insomnia, and bipolar disorders. Varying product compositions showed different effects. Most consistently, high doses of CBD were followed by some acute relief in anxiety, while CBD + THC combinations alleviated withdrawal in cannabis use disorder and improved sleep. In clinical trials, THC was associated most with dose-dependent adverse events and, in some cases, deterioration of primary study outcomes, e.g., in psychosis. In naturalistic studies, participants who used THC reported symptom improvement following usage. Risks of bias across studies were prevalent, and no study found long-lasting medicinal effects or improvement. Overall, medicinal cannabis may provide short-term relief for certain symptoms but is not a cure or without mental health risks.