The Psychological Effects of Marijuana Use:
Two Sides to the Debate Over Prohibition

Mahes Ramachandran
Department of Psychology
Simon Fraser University


Marijuana, cannabis, or hemp is one of the oldest psychoactive plants known to humanity (Grinspoon & Bakalar, 1993). It is botanically classified as a member of the genus Cannabis (Weller, 1983). Cannabis grows all over the world in a variety of climates and soils (Grinspoon & Bakalar, 1993). The fiber has been used for cloth and paper for centuries and was the most important source of rope until the development of synthetic fibers (Grinspoon & Bakalar, 1993).

In the mid 19th century, cannabis came into the West as a medicinal entity, and Western medical literature published more than one hundred papers recommending it for various illnesses and discomforts (Grinspoon & Bakalar, 1993). This trend continued in our century with cannabis proposed as useful medicine for many disorders and symptoms. Although these uses range from the proven to the speculative, they should be of interest to anyone concerned about human suffering.

However, the benefits of any medicine must be weighed against the risks. In opposition to the therapeutic evidence found in medical journals, there is also unusually good evidence of the potential health hazards of marijuana (Hollister, 1986). The dominant fear about marijuana in the 20th century has been that its effects were somehow similar to the dangerously addictive effects of opiates such as morphine and heroine. Despite widespread decriminalization of marijuana in the United States in the 1970s, this concern has remained the basis for federal law and policies regarding the use and study of marijuana. The legal manifestation of this fear is the classification of marijuana as a Schedule 1 drug, a category shared by heroin and other drugs that are banned from medical use because of their high potential for abuse together with the absence of medicinal value. Hence the purpose of this paper is to observe the factors responsible for the categorization of marijuana as a Schedule 1 drug and to challenge its assumption on the medicinal value and high potential for abuse. The secondary component to the paper includes the social implications associated with cannabis together with my feelings and attitudes towards decriminalization marijuana use for medical research.

Health concerns are one of the many reasons which contributed to the placement of marijuana in the Schedule 1 drug category. Researchers both past and present have been interested in its long term effects on the body: link to brain damage, depression of immune system, depression of testosterone levels, chromosomal damage, bronchial and lung damage. In reviewing these literatures, one can observe uncertainty for claiming marijuana to be a dangerous substance as there are no absolute grounds upon which one can be sure to know the long terms effects on the body. Furthermore the drug categorization also neglects the multiple aspects of "set and setting" involved in evaluating marijuana's effects.

The Down Side: Negative Effects of Marijuana Use

Suggestions of long term damage come almost exclusively from animal experiments (Grinspoon & Bakalar, 1993). Observations of long term users in a variety of cross cultural situations such as in Jamaica, Mexico and India reveal little disease or pathology with the use of the drug (Rubin, 1975). For example, there are several reports of damaged brain cells and changes in brain wave readings in monkeys smoking marijuana, but neurological and neuropsychological tests conducted on humans in Greece, Jamaica and Costa Rica found no evidence of functional brain damage (Rubin, 1975). Furthermore, damage to white blood cells has been observed in laboratory studies but the practical (human) implications are unclear (Rubin, 1975). Although marijuana produces temporary changes in the immune system, it has not been found to increase the danger of infectious disease or cancer in humans (Kaslow et al., 1989). If there were significant damage, one would have seen higher rates of these diseases among the 1960s cohort who tried marijuana when it became popular (Grinspoon & Bakalar, 1993). A study conducted on 5000 homosexual men over a period of 18 months showed no correlation between use of marijuana and immune status (Kaslow et al., 1989).

Effects on the reproductive systems of both men and women showed different effects. In men, a single dose of THC lowers sperm count and the level of testosterone (Hollister, 1986). However, in heavy marijuana smokers it has not seen to affect their sexual performance or reproductive capability (Hollister, 1986). In animal experiments, THC is also reported to lower female hormones and disrupt menstrual cycles. When animals were exposed to THC during pregnancy, still births and offspring with lower birth weights were observed. Similar findings were confirmed by some researchers in humans but others fail to demonstrate any effect on the fetus (Fried, 1989). In these situations, controlled experiments are unethical to conduct on humans and furthermore, expectant mothers may be abusing other illicit drugs in addition to marijuana (Fried, 1989). Hence the significance of the research is unclear. However, I believe that expectant mothers should follow strict measures to avoid all forms of drugs for the sake of a healthy child.

The most intriguing physical effect of marijuana is its effects on the pulmonary system. Smoking narrows and inflames the air passages and reduces breathing capacity (Wu et al., 1988). It is found in some studies that heavy marijuana smokers seemed to have damaged bronchial cells (Wu et al., 1988). As marijuana contains 3 times more tar and 5 times more carbon dioxide than tobacco smoke, the effects on the lungs are potentially more dramatic (Wu et al., 1988). However, research reviewing literature over many years found that not a single case of lung cancer, emphysema or other pathology is attributed to cannabis use (Grinspoon & Bakalar, 1993).

Besides the concerns for the long term effects on the body, researchers are also interested in the psychological (addictive or produces dependence) effects of marijuana use. This has been a secondary reason for marijuana being classified as a Schedule 1 drug, because of its high potential for abuse. However various research has contradicted the claim with exceptions for individual differences. According to Grinspoon and Bakalar (1993), two signs of addiction are tolerance and withdrawal symptoms. These symptoms are rarely a problem for marijuana users. After prolonged use of marijuana, tolerance to both the psychological and physiological effects develop. These effects vary among individuals. In various researches conducted, there are no reports of an urgent need to increase the dose or to engage in criminal activity by users to support for their habits. Although a mild withdrawal reaction has been reported in animals and in some humans, it is unclear how common this reaction is. It can be suggested that, in extreme cases, symptoms like anxiety, insomnia, tremors and chills occur and last for about two days but these symptoms are not life threatening.

Furthermore, Grinspoon and Bakalar (1993) stated that dependence on marijuana suggest conflicting assumptions. To differentiate between marijuana use as a cause of problems such as anxiety, depression, boredom and loneliness and the drug use as an effect of these conditions is necessary (Grinspoon & Bakalar, 1993). To alleviate symptoms which are preconditions to the actual effects is a situation that must be taken into consideration. Sometimes the drug causes these states of mind and sometimes they result from personality characteristics that lead to drug use and eventually abuse. Furthermore Ghodse (1986) stated that to claim cannabis causes a functional, paranoid psychosis or a chronic psychosis after drug use ceases is much less convincing. According to him, regular heavy users may suffer repeated short episodes of psychosis and effectively maintain themselves in a chronic psychotic condition. Prolonged effects such as flashbacks and depersonalization may occur because cannabis and its metabolites are eliminated very slowly from the body. Reports of such consequences are often dismissed as anecdotal, and therefore careful analysis is required.

Although one can see discrepancies in the assumptions of the categorization, the fear of the "stepping stone hypothesis" is yet another underlying reason for marijuana to be placed in the Schedule 1 list. The hypothesis claims that marijuana smoking leads to the use of other illicit drugs which are much more potent (Grinspoon & Bakalar, 1993). On the contrary, the authors also suggested that if one smoked marijuana it would be more difficult for anyone to develop interest in opiates or cocaine. Although there is no convincing evidence for the claim, there are numerous instances where marijuana has been used without these drugs and vice versa (Grinspoon & Bakalar, 1993).

Another speculated adverse effect of marijuana is called amotivational syndrome (Weller, 1985). Its symptoms are passivity, aimlessness, sluggishness, uncommunicativeness and lack of ambition (Grinspoon & Bakalar, 1993). Since amotivational syndrome is not prevalent in the cross cultural studies (usually conducted on farmers and other blue collar workers), Rubin (1975) suggested that only skilled and educated people are affected as they engage in more complex cognitive tasks in their daily routine. In addition, Brill (1982) revealed no significant differences in GPA of users and nonusers, nor in the frequency with which they dropped out of college.

As motivation and ambition are important to successful functioning in modern society, any adverse effects could have important consequences and this might be another reason for officials to place marijuana in the Schedule 1 drug category. Although the assumption is not directly presented, it may be a contributing factor to the decision. Fortunately, most marijuana users do not appear to develop amotivational syndrome (Weller, 1985). But the link between amotivation and marijuana use is not well understood and requires further research.

In reviewing the possible health effects on marijuana users, it is important to see how this drug serves as a therapeutic agent despite the claim of having no medicinal value as a Schedule 1 of the Drug Enforcement Administration's controlled substance list.

Medicinal Uses of Marijuana

Chemotherapy is one of the most important cancer treatments developed in the past several decades, however, chemotherapeutic agents are among the most powerful and toxic chemicals used in medicine (Hollister, 1986). In attacking cancer cells, they also kill healthy body cells, producing unpleasant and dangerous side effects. In place of standard drugs, marijuana may be a remarkably effective substitute (Hollister, 1986). A research conducted by Moore and Brennan (1988) suggested that 56 of the cancer patients who smoked marijuana as treatment, 78% became symptom-free. This shows that more than half of the cancer patients got relief from using marijuana without any undesirable side effects as in chemotherapy.

Another medicinal condition that marijuana has been used to treat is glaucoma, a disorder that results from an imbalance of pressure within the eye (Hollister, 1986). Presently the disorder is treated with eyedrops containing beta blockers which inhibit the activity of the epinephrine (Hollister, 1986). They are highly effective but also have serious side effects: depression, asthma, slow heart rate, and increase of heart failure (Hollister, 1986). Fifty percent of glaucoma patients cannot tolerate the side effects of these drugs. Several researchers in Hollister's review conducted experiments on both humans and animals and found that marijuana may be useful in treating glaucoma. It was found that under its influence the pupils responded normally to light, visual acuity, refraction, peripheral visual fields, binocular vision and color vision were not affected (Hollister, 1986). Subjects in the study did not develop tolerance to the drug during their 94 days and no further deterioration of the vision was observed.

Two other common uses of cannabis in the 19th century were for the treatment of menstrual cramps and reduction of labour pains. Although there is no current medical literature available to support this treatment, many women who have used cannabis reported the relief of menstrual cramps (Hollister, 1986).

Furthermore, a study conducted by Shapiro, Lee and Harper (1975) on the effects of marijuana on asthma patients showed that higher dose administration allowed for better results in treating asthma patients than in administering lower doses. However, patients improvements were still significant with the baseline. In other words, results were too low/small to support that marijuana use cured asthma. The sensitivity of the respiratory tracts was not altered by either dose, indicating no central respiratory depression.

Marijuana Use and Social Concerns

In assessing the adverse health effects of cannabis, there is a question whether the acute experience can in reality cause harm to the individual and to society as a whole. It would seem probable that any acute psychotic experience may put the individual at risk (Graham, 1976). For example, the possibility of acting out one's paranoid fears in terms of violence, accidental self-injury or purposive suicide (Graham, 1976). Such an assertion is balanced by the insufficient data for real frequency of such events relating directly to marijuana.

Although there has been no evidence reported about "flashback" cases related to marijuana use and that the more unpleasant reactions to marijuana are reactively short-lived, it should be noted that the possibility of complex interference with brain damage and its functioning should not be dismissed as neuro-scientists have little to say on this as yet (Graham, 1976).

If it was established that heavy and prolonged use of cannabis resulted in great social incapacity (i.e., the inability to perform efficiently in school, work or family), there would be a concern for its adverse effects. It is such speculative fears that forbid the legalization of marijuana and place it under the Schedule 1 drug category. To dismiss such fears on present evidence of amotivational syndrome and achievement would be premature. Hence the real likelihood of social risk from cannabis should be guarded.

A study conducted by Digregorio and Sterling (1987), suggested that smoking only two marijuana cigarettes can impair perception and motor coordination enough to affect driving. For example, a red light may appear and the person high on marijuana maybe unable to stop his/her vehicle. Furthermore, evidence shows that a decrease in the concentration during driving makes it difficult to accurately estimate time and distance, depth perception and to adjust to glare. A person who is socially high loses approximately 40% of his/her psychomotor function. This impairment is dose related and the effects can last up to several hours (Digregorio & Sterling, 1987). Driving under the influence of alcohol and drugs contributes to the growing problem of traffic accidents. Studies conducted by Turner (1983) supported the last mentioned claim, showing that 16% of the victims of fatal accidents were users of marijuana. Since insurers pay the cost not to mention loss of life and injury, government has started programs to educate people about driving under the influence of marijuana and alcohol.

Furthermore, Hass and Hendin (1987) have shown that marijuana use over long periods of time was not found to be linked with maladaptive functioning in a behavioral sense. The large majority of these adults were clearly functioning adequately from the viewpoint of societal standards for occupation and personal success. As revealed from the questionnaire used in this study, subjects were, for the most part, gainfully employed, their patterns of social relationships were normative and their responses reflected generally high level of satisfaction with themselves and their lives. Therefore, it is not clear to what extent marijuana use creates social problems in a society.

Summary and Conlcusion

In presenting both sides of the presumed health effects and therapeutic agent, I personally support the decriminalization of marijuana for reasons mentioned below. As assumptions of the Schedule 1 drug category did not match the research literature in terms of its absence in medicinal value and high potential for abuse, I am doubtful of the validity of the categorization. The American government is unwilling to admit that marijuana can be safe and effective medicine because of a stubborn commitment to wild exaggeration of its dangers when used for other purposes. Far from believing that medicinal availability of marijuana would open the way to other uses, I take the view that free availability of cannabis may be the only way to make its medical use possible. Marijuana should be available for use in much the same way alcohol and tobacco are now available. As I noted earlier, cannabis lost its medical status as a result of placing the substance in the Schedule 1 category with assumptions of no medicinal value. The full potential of this substance including its medicinal potential will be realized when we end the prohibition established by the government some 25 years ago in 1970.

This paper was mainly written to challenge the assumptions of the Schedule 1 drug category which includes marijuana as a substance with high potential for abuse and with no medicinal value. However there are legitimate concerns about anyone driving under the influence of marijuana, having drug dependence problems and experiencing long term physical and psychological effects. Recognizing these effects and taking relevant precautions will make one a more responsible individual in using marijuana in one's society. In reviewing various research reports, one can notice the uncertainty researchers face is labeling marijuana as a therapeutic agent or as a substance with high potential for abuse. As the full impacts of marijuana use are currently unknown, categorizing the substance under the Schedule 1 list is an unfair act to continue.


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