Drug Watch International

MARIJUANA RESEARCH REVIEW

Study shows MS patients further impaired by smoking low-THC marijuana

Greenburg et al, in their paper in Clinical Pharmacology and Therapeutics, Vol. 55:324-328,1994, performed a double-blind randomized, placebo-controlled study of inhaled marijuana smoke on balance and coordination responses in ten adult patients with spastic multiple sclerosis, and normal volunteers who were matched for age, sex, and weight. A sophisticated computer-controlled video system was used to identify responses. The study showed that marijuana smoking enhanced the abnormalities already present in MS patients and that smoking just one marijuana cigarette containing 1.5% delta-9 THC increased the objective errors in these responses. The authors concluded that marijuana smoking impairs coordination and balance in patients with spastic MS.

Commentary: This is an objective and well­-done controlled study which strongly refutes anecdotes suggesting that marijuana is beneficial for patients with multiple sclerosis. In the absence of data showing any benefit, this documentation of an adverse effect is disturbing and should be heeded by those who would consider using smoked marijuana for treatment of this disorder. ##

Low does of THC found to cause learning deficits

Kamine et al, in their article in Behavior of Pharmacology, Vol. 5:71-78,1994, studied the effects of delta-9 tetrahydrocannabinol (THC) on the learning and performance ability of eight healthy subjects (19-32 years of age) all of whom had occasionally used marijuana, as well as other psychoactive drugs, but were not perceived to be drug dependent. Subjects were give placebo capsules, and 10 mg. and 20 mg. capsules of THC, ~ roughly equivalent to smoking a marijuana cigarette containing 2.3-3.6% THC")

Oral THC caused measurable learning deficits which, the authors concluded, might be disastrous in some environments, such as operating "the cab of a speeding locomotive." They pointed out that the "learning deficit from a single dose might become quite relevant if it cumulates over time."

Commentary: In regular marijuana users, the presence of a learning deficit with a single dose of drugs and five hours of post-therapy monitoring is sobering. It view of the greatly increased potency of marijuana over the past decade and the recent rise in its use by teenagers and pre-adolescent children, this should be particularly alarming to parents and educators. This report contributes to the body of evidence showing that "recreational use of marijuana is not a benign habit in terms of intellectual performance." ##

Marijuana's implication in a number of chronic diseases reflects its harmful impact on the immune system

Immune defenses against fungal organisms are triggered by natural killer cells. If this system is upset, the susceptibility to fungal infections is enhanced. Cusher et al, in their report in Cellular Immunology (Vol. 154:99-108,1994) incubated human large granular lymphocytes (human immune cells) with varying concentrations of THC (delta-9-tetrahydrocannabinol). The concentrations used mirrored what would be obtained in the blood of people smoking marijuana or taking the drug dronabinol. They found that low levels of THC inhibited tumor necrosis factor and weakened the killing activity of lympho­cytes against tumor cells.

Commentary: It is well-known that substance abuse may compromise immune response to a variety of infectious agents. Marijuana, a widely abused drug around the world, and its components, have adverse effects on the immune system. This study is another of a series showing that, in the test tube, concentrations of the major psychoac­tive metabolites of marijuana are capable of impairing the ability of human immune cells to kill tumors and destroy fungal cells. The importance of this report is that the relatively low concentrations which mimic drug use in humans, cause these profound depressions of immune activity. ##

Marijuana not listed in latest review of beneficial treatment for Multiple Sclerosis

Because of frequent claims that smoking marijuana provides therapeutic benefit to victims of multiple sclerosis the extensive and well documented review of all the effective therapies for treatment of this disease, by G. C. Eber, The Lancet, Vol. 343, January 29,1994, is included in this publication.

Eber notes in his review that multiple sclerosis (MS) "... is unpredictable, being characterised by a tendency to relapse and remission and/or to stabilisation without treatment." He notes that the natural history of the disease is well-defined and states that trial and error can no longer be reasonably applied to the search for effective therapies. Eber concludes that although clinical symptoms and anecdotes are valuable, highly sensitive objective methods are now available in the form of serial MRI scans to document improvement of the disease with such exciting therapies as beta-interferon.

Commentary: This extremely complete review of multiple sclerosis therapy puts to rest any contention that smoked marijuana is good for this disorder and can be given without side effects. There simply are no data to support the safe or effective use of either smoked marijuana or dronabinol for treatment of MS. Eber's warning of the need for objective data when judging a therapy for this complex disease is well worth heeding. ##

Marijuana use linked to homicide

In terms of life-time use, marijuana was reported to be the most common illicit drug used by a sample of 268 murderers incarcerated in New York State correctional facilities, for homicides that occurred in 1984. Spunt et al ("The Role of Marijuana in Homicide" International Journal of the Addictions, Vol.29:195-213,1994)

About one-third of prisoners who had used marijuana, had used it in the 24-hour period before the homicide, and three-quarters of those said they experienced some kind of effect from the drug when the homicide occurred. The authors speculate that drugs and violence may be linked in a variety of complex ways.

Commentary: It is clear that abnormal behavior induced by the use of psychoactive­ drugs plays a significant role in violent crimes which are completely unrelated to either drug profits or trafficking. Many of the murderers interviewed for this study stated they felt that marijuana use was a factor in their crimes. Recent well-publicized violent murders, such as the tragic rape and murder of 12 year-old Polly Klaus, were also committed by people testing positive for marijuana at the time of their homicides. ##

------------------------------

Material used in this publication has been reviewed and commented on by William M. Bennett, M.D., Professor of Medicine, Division of Nephrology, Clinical Pharmacology and Hypertension at Oregon Health Sciences University, Portland, Oregon

Drug Watch Oregon
P.O. Box 5853, Portland, Oregon 97228-5853
Phone/Fax: 360-263-3964
Email address: MJRRview@aol.com

Return to Drug Watch International Homepage

This page was last updated on July 03, 2001
Copyright © 2001 Drug Watch International. All rights reserved. Disclaimer
Please address all comments and questions to:  Drug Watch International, P.O. Box 45218, Omaha, NE  68145-0218, USA