The only properly design ed , low bias and highly powered study found a weight increasing effect  of dronabinol in AN , while the other , using Δ9-THC at a high dose , found no effect and where the dose may have counteracted the weight gaining effects due to adverse events .
Anorexia nervosa ( AN ) is a psychiatric disorder with a high mortality and unknown etiology , and effective treatment is lacking .
For decades , cannabis has been known to cause physical effects on the human body , including increasing appetite , which may be beneficial in the treatment of AN .
To systematic ally review the literature for evidence of an effect of cannabinoids on ( 1 ) weight gain , and ( 2 ) other outcomes , in AN .
How effective and safe is medical cannabis as a treatment of mental disorders? A systematic review
We conducted a review of systematic review s ( SRs ) and r and omized-controlled trials ( RCTs ) to analyze efficacy and safety of cannabis-based medication in patients with mental disorders . Five data bases were systematic ally search ed ( 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 assessment s , consistent outcome measures and active comparisons are needed
The only properly design ed , low bias and highly powered study found a weight increasing effect  of dronabinol in AN , while the other , using Δ9-THC at a high dose , found no effect and where the dose may have counteracted the weight gaining effects due to adverse events .
Anorexia nervosa ( AN ) is a psychiatric disorder with a high mortality and unknown etiology , and effective treatment is lacking .
For decades , cannabis has been known to cause physical effects on the human body , including increasing appetite , which may be beneficial in the treatment of AN .
To systematic ally review the literature for evidence of an effect of cannabinoids on ( 1 ) weight gain , and ( 2 ) other outcomes , in AN .