Study Shows Therapeutic Benefits, No Adverse Effects in Long-Term Marijuana Users

Missoula, MT: A battery of medical tests on a cohort of chronic, legal medical marijuana smokers reveals no significant physical or cognitive impairment attributable to marijuana, according to preliminary results of a recent study. All four patients examined in the study are participants in the FDA/NIDA (National Institute on Drug Abuse) Compassionate Investigational New Drug (IND) program, and have been smoking government-grown pot daily for more than a decade.

"This data agrees with the results of other chronic use studies performed in the 1970s in Jamaica, Costa Rica and Greece that found no significant attributable health problems in cannabis smokers. However, this study is the first of its kind to examine chronic cannabis usage in medical patients using a consistent source of medicine of known potency," said Dr. Ethan Russo, who headed the study.

Russo did observe "mild changes in pulmonary function" in three of the four patients, but noted these changes weren't significant nor was there any evidence of malignancy. He speculated that the changes could be at least partially due to the weak potency of government-grown marijuana and its large content of fibrous material.

No other tests, including MRI brain scans, chest X-rays, neuropsychological tests, immunological assays, and EEGs showed any significant adverse side-effects attributable to marijuana.

In addition, the study affirmed pot's therapeutic value for a variety of symptoms. The results demonstrate clinical effectiveness in these patients in treating glaucoma, chronic musculoskeletal pain, spasm and nausea, and spasticity of multiple sclerosis, the study's authors wrote. They maintain that all four patients are stable with respect to their chronic conditions, and are taking many fewer standard pharmaceuticals than before they began using medical cannabis.

This study is believed to be the first to examine the overall health status of medical marijuana patients in the IND program. That program began distributing medical pot to patients in 1976, but was closed to new applicants in 1992. Seven surviving patients remain in the program, though their health status is monitored by their individual physicians. Neither the FDA nor NIDA has previously published any follow-up studies on this group of patients.

The study was funded in part by grants from MAPS (The Multidisciplinary Association for Psychedelic Studies), philanthropists John Gilmore and Preston Parish, and the Zimmer Family Foundation.

A full report of the study will appear in the January 2002 issue of The Journal of Cannabis Therapeutics, published by Haworth Press.

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