Results from a 3-year clinical study confirm for the first time that THC can help patients with anorexia nervosa gain weight.
While marijuana is known to increase appetite, the study was the first to confirm the effectiveness of its main chemical, THC, in patients with the eating disorder.
Anorexia nervosa affects women more often than men and is caused by an irrational fear of gaining weight, leading to restricted food intake and excessive weight loss.
Researchers at the Center for Eating Disorders at Odense University Hospital in Denmark monitored 24 women with severe, long-lasting anorexia nervosa who were given synthetic THC pills (dronabinol) as part of a randomized controlled crossover trial.
The findings were released last month in the International Journal of Eating Disorders.
Dronabinol therapy was well tolerated. During four weeks of exposure it induced a small but significant weight gain in the absence of severe adverse events.
Patients were split into two groups and received 4 weeks of daily dronabinol and placebo in succession, with a 4 week break for washout in between.
On average, patients gained 0.73kg more during the 4 weeks of dronabinol treatment compared with 4 weeks of receiving placebo. While only a modest improvement, the authors suggest that a longer treatment period might produce more significant benefits.
Side effects were not officially measured, but the authors noted minimal adverse reports. Results from the one year follow-up also confirmed the safety of THC therapy.
Weight records collected up to one year after the end of the trial showed that the participants continued to improve their nutritional status without developing addiction or withdrawal symptoms, suggesting that dronabinol was safe in these patients with longstanding AN [anorexia nervosa].
According to the authors, the latest study was the first in over 30 years to investigate THC’s potential in anorexia nervosa. Previous studies on THC and weight gain have only involved patients suffering from anorexia caused by diseases such as cancer and AIDS.
However, because of the small sample size of the study, the authors say that larger studies are needed before THC can be widely recommended as a treatment for anorexia nervosa.
The study was published ahead of print and supported independently by the Center for Eating Disorders, Department of Endocrinology, Odense University Hospital