METHODS:
We studied 21 patients (mean age, 40 ± 14 y; 13 men) with Crohn's Disease Activity Index (CDAI) scores greater than 200 who did not respond to therapy with steroids, immunomodulators, or anti-tumor necrosis factor-α agents. Patients were assigned randomly to groups given cannabis, twice daily, in the form of cigarettes containing 11.5 mg of tetrahydrocannabinol (THC) or placebo containing cannabis flowers from which the THC had been extracted. Disease activity and laboratory tests were assessed during 8 weeks of treatment and 2 weeks thereafter.

RESULTS:
Complete remission (CDAI score, <150) was achieved by 5 of 11 subjects in the cannabis group (45%) and 1 of 10 in the placebo group (10%; P = .43). A clinical response (decrease in CDAI score of >100) was observed in 10 of 11 subjects in the cannabis group (90%; from 330 ± 105 to 152 ± 109) and 4 of 10 in the placebo group (40%; from 373 ± 94 to 306 ± 143; P = .028). Three patients in the cannabis group were weaned from steroid dependency. Subjects receiving cannabis reported improved appetite and sleep, with no significant side effects.

CONCLUSIONS:
Although the primary end point of the study (induction of remission) was not achieved, a short course (8 weeks) of THC-rich cannabis produced significant clinical, steroid-free benefits to 11 patients with active Crohn's disease, compared with placebo, without side effects. Further studies, with larger patient groups and a nonsmoking mode of intake, are warranted.

Often mischaracterized as an autoimmune disease, Crohn's disease is in fact an immune deficiency state. Arising from a host of genetic, environmental, and immunological factors, the disease causes a chronic inflammatory disorder that attacks the person's gastrointestinal tract — anywhere from the mouth to the anus — in order to fight the body's antigens that otherwise do no harm. Symptoms of the disease range from mild abdominal pain to more severe cases of bloody diarrhea, nausea, vomiting, weight loss, and fevers.

There is no cure for Crohn's; however, various methods are aimed at limiting flare ups and keeping the disease in remission. Treatments, like disease severity, fall on a spectrum depending on the person. Simple dietary changes suffice for some, while invasive surgery to remove the affected area may be needed for others. Corticosteroids and other medications are also prescribed for less severe cases.

The disease affects around 400,000 to 600,000 people in North America, although many people do not get diagnosed until they've had the disease for years, simply because no symptoms were present.