Drug Watch International

MARIJUANA RESEARCH REVIEW

Cannabis use found to increase frequency of relapse in patients with schizophrenia

The literature examining the relationship between marijuana use and schizophrenic symptoms among patients with schizo­phrenic disorders has been conflicting. The purpose of this study by Linzen et al (Archives General Psychiatry, Vol.51, pg. 273-279,1994), was to compare cannabis-using schizophrenic patients with schizophrenic non-users. There were 11 mild and 13 heavy cannabis users compared to 69 non-users in a prospective study which lasted one year. The authors found that significantly more and earlier psychotic relapses occurred in the cannabis-using group, particularly as use increased. No other factors could be found to explain this including other street drugs.

Fourteen of the cannabis-using patients, who were experiencing clinical remission from their schizophrenia, reported an immediate increase in psychiatric symptoms after using cannabis again.  

In all but one of the patients cannabis use also preceded the onset of their first psychotic symptom. Over the one-year period only 20 percent of the non-using subjects had a psychotic relapse, as compared to 46 percent for those who used cannabis.  

Commentary: This study helps to clarify the relationship between cannabis use and schizophrenia. While studies such as this cannot prove cause-and-effect relationships, it is clear that use of cannabis can cause patients with psychiatric disorders, such as schizophrenia, to have more frequent relapse of symptoms compared to non-users of cannabis. An important feature of this study was that the groups were matched for variables, such as the use of other street drugs or alcohol, making these factors not relevant in interpretation of the results. Findings of this study are consistent with the observations of prior studies showing that cannabis use prior to illness was an independent risk factor for schizophrenic symptoms. ##

Smoking tobacco or marijuana reduces antioxidant levels in HIV-infected patients

Miguez-Verbano and colleagues from the University of Miami School of Medicine reported at the American College of Clinical Pharmacology meeting in 1994 that anti-oxidant status was negatively impacted in 60 non-symptomatic HIV-infected marijuana smokers.

Vitamin E levels were significantly lower in marijuana users, as well as cigarette smokers, compared to non-smoking HIV infected subjects. Subjects who used both tobacco and marijuana exhibited frank vitamin E deficiency, although vitamin E intake did not differ significantly among the groups.

These findings show that marijuana and tobacco smoking have a detrimental effect on vitamin E status of HIV-infected individuals. This is of concern in light of the important role of vitamin E in immune processes, including inhibition of viral activation.

Commentary: This well done study shows further evidence that smoking marijuana contributes to defects in the immune system. The issue of smoking marijuana for an HIV-infected patient makes absolutely no sense in terms of preserving immune function to fight the virus that causes the disease. Antioxidant levels also have an important effect on preventing cardiovascular disease and cancer, both of which would be important in HIV-infected individuals. ##

Study examines the use of psychoactive and addictive drugs by physicians

Lutsky et al studied the current use of psychoactive drugs of abuse by physicians specializing in medicine, surgery, and anesthesia, all of whom had trained at the same academic institution. (Canadian Journal of Anaesthesia 1994/41:7/pp 561-7) 1624 questionnaires were sent with a response rate of 58 percent.

Difference in impairment rate among the physicians was not significant: in surgery 14 percent, medicine 20 percent, and anesthesia 17 percent. Substance abuse was clearly associated with a family history of substance abuse. Increased stress at various career stages did not appear to increase substance abuse. Substances most frequently abused were marijuana 55 percent, amphetamines 33 percent, and benzodiazepines 25 percent.

A number of respondents reported that the use of alcohol and drugs by faculty role models during their medical training was an important part of their own personal use. Drug counseling programs and diversion programs were judged inadequate by most respondents.

Commentary: No subset of society is immune from substance abuse in a modern social context. Obviously, better detection and treatment programs are necessary for the prevention and control of this problem, which impairs medical judgment and places patients interests at great risk.

In the United States, only 3 percent of practicing physicians are anesthesiologists, yet 13 percent of physicians being treated for drug dependency are anesthesiologists, presumably because of the ease of access to these substances in this medical specialty.

The data from this survey pointed out that most drug use started prior to entry into medical school. The authors suggested that programs aimed at deterrents failed at least partially because there are no universally acceptable drug screening methods, and because penalties for drug use are insufficiently severe. Substance abuse by faculty represented another setback to any prospect for deterring physicians in training. ##

Study shows two marijuana cigarettes as harmful as 28 of tobacco

This study by Starr et al. followed 25 non-tobacco smoking surfers, in excellent physical condition, who smoked an average of two marijuana joints per day. The control was 25 male urban smokers from the San Francisco area and 25 non-smoking male Mormons from the Silicon Valley area. Damage and irritation to the lung cells of the marijuana smokers was comparable to those who smoked a mean of 28 tobacco cigarettes per day. (Medical Tribune, page 17,1994)

Commentary: Tobacco smoke is the most widespread factor associated with premature death due to cancer and cardiovascular disease in the USA. This study shows that cellular damage to the lungs produced by daily use of two marijuana cigarettes is similar to that seen in those who smoke nearly a pack and a half of tobacco cigarettes a day. ##

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

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