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 .
Changes in IGF-I, urinary free cortisol and adipokines during dronabinol therapy in anorexia nervosa: Results from a randomised, controlled trial.
OBJECTIVE Anorexia nervosa ( AN ) is characterised by complex neuroendocrine disturbances due to severe underweight , physical hyperactivity and purging behaviour . Cannabinoid agonists are used to palliate cachexia of various causes , but their interactions with the hormonal systems that are involved in energy metabolism have not been previously described in humans . Therefore we found it of interest to assess interactions between the synthetic cannabinoid agonist dronabinol and insulin-like growth factor I ( IGF-I ) , urinary free cortisol ( UFC ) and adipokines in patients with chronic AN . DESIGN This was a prospect i ve , double-blind r and omised crossover study , conducted at a specialised care centre for eating disorders . The results are based on twenty-four adult women with chronic AN , who completed the study . The participants received dronabinol ( oral capsules , 5 mg daily ) and matching placebo over four weeks , separated by a four-week washout period . Bioactive IGF was determined by a cell-based bioassay , whereas total IGF-I , IGFBP-2 and -3 and the two adipokines leptin and adiponectines were measured by immunoassays . The UFC excretion was determined by mass spectrometry . RESULTS As previously reported , dronabinol treatment caused a small , yet significant increase in BMI as compared to placebo ( + 0.23 kg/m(2 ) ; P = 0.04 ) . This modest weight gain predicted a corresponding increase in bioactive IGF-I , while the amount of daily energy expenditure due to physical activity had a comparable but opposite effect . Nevertheless , neither IGF-I , bioactive IGF nor the IGFBPs levels changed significantly during dronabinol intervention as compared to placebo . Adiponectin also remained unaffected by the weight gain , whereas plasma leptin showed a transient increase at three weeks ( P < 0.05 ) . UFC levels were decreased during dronabinol intervention . CONCLUSION Our results showed that low-dosage therapy with the synthetic cannabinoid agonist dronabinol affected neither the concentration nor the activity of the circulating IGF-system in women with severe and chronic AN . However , our results suggest that such treatment may alleviate the increased hypothalamic-pituitary-adrenal axis activity seen in these patients
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 .