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 .
Blood Levels of the Endocannabinoid Anandamide are Increased in Anorexia Nervosa and in Binge-Eating Disorder, but not in Bulimia Nervosa
The endocannabinoid system , consisting of two cannabinoid receptors ( CB1 and CB2 ) and the endogenous lig and s an and amide ( arachidonoylethanolamide ( AEA ) ) and 2-arachidonoylglycerol ( 2-AG ) , has been shown to control food intake in both animals and humans , modulating either rewarding or quantitative aspects of the eating behavior . Moreover , hypothalamic endocannabinoids seem to be part of neural circuitry involved in the modulating effects of leptin on energy homeostasis . Therefore , alterations of the endocannabinoid system could be involved in the pathophysiology of eating disorders , where a deranged leptin signalling has been also reported . In order to verify this hypothesis , we measured plasma levels of AEA , 2-AG , and leptin  in 15 women with anorexia nervosa ( AN ) , 12 women with bulimia nervosa ( BN ) , 11 women with binge-eating disorder ( BED ) , and 15 healthy women .  Plasma levels of AEA result ed significantly enhanced in both anorexic and BED women , but not in bulimic patients . No significant change occurred in the plasma levels of 2-AG in all the patients ' groups . Moreover , circulating AEA levels were significantly and inversely correlated with plasma leptin concentrations in both healthy controls and anorexic women . These findings show for the first time a derangement in the production of the endogenous cannabinoid AEA in drug-free symptomatic women with AN or with BED . Although the pathophysiological significance of this alteration awaits further studies to be clarified , it suggests a possible involvement of AEA in the mediation of the rewarding aspects of the aberrant eating behaviors occurring in AN and BED
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 .