"The Dangers of Marijuana, A Warning!"

by David Harvey Powelson, M.D.

This Statement was made before the Senate Judiciary Committee

In 1965, I was chief of the Department of Psychiatry in the Student Health Service at the University of California in Berkeley. It was the first year of the student riots. It was also the first year that hallucinogens were becoming widely used and I, as the person responsible for mental health on the campus, was vigorously involved in the debate about pallocybin, LSD, and mescaline.

In the spring of that year a reporter for the Daily Californian, the student newspaper, asked for my opinion on marijuana. At that time I lacked any direct experience as a physician with marijuana users. The medical literature was sparse, but in general seemed to be saying that there was no proof of long-term harmful effects from marijuana. I summarized this for the reporter and said there was no proof of harm and that it should be legalized and controlled. In general, this view met with approval from most of the students and most of my professional colleagues.

In 1965, the use of marijuana spread through the Berkeley campus. Simultaneously its use was spreading to all the colleges and universities across the country. From the campus communities it spread at an accelerating rate through the surrounding communities. By now its use is subject to no age, social, or geographical barriers.

My place of observation was unique. I was routinely meeting with deans and administrators who were dealing with the drug problem and the students who were in academic and disciplinary difficulties as a consequence of the use of marijuana and its derivatives.

Most importantly, I was in daily contact with the constant flow of students through the student health service and the psychiatric clinic and hospital.

During this time (1965-1972) an increasing number of patients were using marijuana. My best guess, based on surveys and impressions, is that more than 80 per cent used it at one time or another in college. More than 50 per cent used it "socially" (1-2 times per week), and about 10 per cent were heavy users (at least 1 time daily).


My first important shift in thinking occurred as a result of observations made during psychotherapy with a young man, S., who was bright enough to be getting his law degree and Ph.D simultaneously and competent enough to be learning to fly and deal in real estate at the same time. As we proceeded in our work together, I came to know S.'s way of thinking: i.e., how he thought. Most of us do this without thinking about it. All of us come to know to some degree the way our friends and colleagues think. In therapy, the opportunity to hear someone think out loud about a problem important to him maximizes the opportunity to come to know how he uses or misuses logic, remembers clearly or not at all, does or does not exercise good judgment about his own thinking, and whether he is able to know his own feelings. We had made enough headway so that S. had begun to be able to observe and understand his own thinking. Periodically, we had hours (I was seeing him twice weekly) when his thinking became mushy. If I tried to follow him, my head began to spin. When I protested that he'd become impossible to listen to, he'd argue that his own experience was that he was thinking more clearly, more insightfully, then ever. On one such occasion, he mentioned that he'd been to a party two nights before where he'd had particular good "grass." In Berkeley, 1968, that was not a particularly memorable remark, but we thought there might be some connection with his thinking. This same series of events recurred often enough so that I finally was able to post dict [diagnose after the fact] that S. had some "mind-expanding drug," usually marijuana.


S., because he was a good observer, helped show me another aspect of the thinking disorder I'm describing. Central to his difficulties was a paranoid stance toward the world. By this I mean a style of thinking characterized by a constant suspicion that one is being controlled; e.g., by the establishment, the system, etc.; and simultaneously a constant unwitting search for people and situations which will do just that; e.g., drugs, demagogues. If this manner of thinking is carried further, it blends into the condition usually called paranoia. Here the subject is controlled by voices, God, or whatever, and at the same time, he is very often "against his will" being controlled by a state hospital or jail. S. was forever talking about his search for someone or something he could trust. He very frequently clutched to himself people who were totally untrustworthy and hurt and rejected others who manifestly admired him.

When he had used marijuana, his thinking became more paranoid, i.e., he became more mistrustful of me, for instance, and at the same time, he became more wily so that he talked glibly, using cliches, theories, and "insights," all to avoid noticing concretely and immediately whatever he was really doing and feeling in his relationship with me, as well as his relationships outside. In short, the pathological part of his thinking was exaggerated in two ways:

(1) he was more suspicious and

(2) he was more adept at fooling himself about what he was up to, while simultaneously maintaining how "aware," "in touch," and "loving" he was.

S. continued in therapy but also continued to use marijuana and hashish. Toward the end of his therapy I decided that so long as he muddied his thinking in this way, there was no use continuing. He, however, suffered a fatal accident (as a result of an error in judgment) before his therapy was terminated.


As I was becoming familiar with these effects of marijuana on S., I gradually learned to pick up signs when they were more subtle. I came to observe the same changes in others, i.e., that marijuana exacerbated the pathological aspects of their thinking.

Following the above described observations, I saw the same picture more and more frequently. The essence of the pattern is that with small amounts of marijuana (approximately three joints of street grade), memory and time sense are interfered with. With regular usage the active principles cause more and more distorted thinking. The user's field of interest gets narrower and narrower as he focuses his attention on immediate sensation. At the same time his dependence and tolerance is growing. As he uses more of the drug, his ability to think sequentially diminishes. Without his awareness, he becomes less and less adequate in areas where judgment, memory, and logic are necessary. As this happens, he depends more and more on pathological patterns of thinking. Ultimately all heavy users (i.e., daily users) develop a paranoid way of thinking.


After I had become aware of the generality of this sequence, another reporter from the Daily Californian interviewed me to see if my opinions had changed in the interim. In the course of that interview, I realized in a concrete and explicit way that they had. The headline read, "Psychiatrist says pot smokers can't think straight." This time the response of the community and colleagues was not so approving. It is an interesting fact that questioning the claims of marijuana users leads to much more anger, vilification, and character assassination than does the opposite stance.


In subsequent years in Berkeley, both at the clinic and in my private practice, I have observed the long-term effects of cannabis. Originally, my observation was that students who had "dropped out" into the "drug scene" and were attempting to return were finding it difficult if not impossible. A frequent story is that the young person has become aware that the life he's been leading is unsatisfactory and unproductive. He then stops drugs for six months or so and re-enters the university. When he returns to school, however, he finds that he can't think clearly and that, in ways he finds difficult to describe, he can't use his mind in the way he did before. Such people also seem to be aware that they've lost their will some place, that to do something, to do anything, requires a gigantic effort; they have become will-less--what we call anomic. They need an external director. They are ripe for a demagogue. [One cannot help but recall the Manson "family," the young women who were attracted to the dynamic, charismatic leader, Charles Manson, and who were described as "anomic", having no active personality or wills of their own, obeying Charles Manson their cultic leader in such an unquestioning way that they participated with him in the most gruesome murders of Sharon Tate and others in the celebrity's Hollywood home.]

The changes in the capacity to think in some subjects are long lasting, if not permanent. One of my original (1967) subjects was a member of the junior faculty. He "dropped out" and used hashish exclusively for 18 months in daily doses. When he realized that it was interferring with his physical coordination, he stopped all drugs. Two years subsequent to this he returned to the university. He found that he could not do mathematics at a level which he had found possible before. Three and a half years later, his conviction was that the change was permanent. My own observations of him and other such gifted people have led me to the same conclusion, that the damage may be permanent.

My stance toward marijuane has shifted to the extent I now think it is the most dangerous drug we must contend with for the following reasons:

1. Its early use is beguiling. It gives the illusion of feeling good. The user is not aware of the beginning loss of mental functioning. I have never seen an exception to the observation that marijuana impairs the user's ability to judge the loss of his own mental functioning.

2. After one to three years of continuous use, the ability to think has become so impaired that pathological forms of thinking begin to take over the entire thought process.

3. Chronic heavy use leads to paranoid thinking.

4. Chronic heavy use leads to deterioration in body and mental functioning which is dificult and perhaps impossible to reverse.

5. For reasons which I can't elucidate here, its use leads to a delusional system of thinking which has inherent in it the strong need to seduce and proselyte others. I have rarely seen a regular marijuana user who wasn't actively "pushing."


As these people move into government, the professions, and the media, it is not surprising that they continue as "pushers," thus continuously adding to the confusion that this committee is committed to ameliorate.--

1974 Issue of "Drug Enforcement" Vol. 1, No. 5 Published by the Drug Enforcement Administration. U.S. Department of Justice, Washington, D.C. 20537.

Note on the above last paragraph: If marijuana use is as harmful and damaging and even irreversible as Dr. Harvey Powelson found it to be in his own psychiatric practice, it is going to be a question for credible historians, if it is not already, how much marijuana use affected the minds of William Clinton, George W. Bush, and Barack Hussain Obama, possibly causing them to behave the way they did in regard to various issues of national security. We also wonder how much marijuana use has influenced the behavior and critical thought processes of the Baby Boomer generation presently running things in the U.S. government, the media, and the professions. Isn't it possible that this drug has contributed significantly, and even greatly, to the disastrous moral and intellectual decline of the U.S.? It certainly seems to explain the paranoia, the obsessive hero worship, and the uncritical focusing on strong leaders and Big Government that characterizes the Left.

What with California lately legalizing marijuana, we may see a major shift toward this "harmless and medicinal" drug. Why should any food be grown in California's vast breadbasket of the Imperial Valley, when marijuana brings in a hundred times more as a cash crop? Already, before the legalization of pot, it was the biggest cash crop in the state while being grown on tiny, illicit plots hidden in the hills and mountains and on state park lands. Now California, with its massive agriculture rapidly converted to pot growing, may soon become the world's supplier of the drug, and the states that still ban it will be flooded with it anyway. As California goes, so goes the nation in so many cases. We may see America succumb to the avalanche of Californian-grown pot in a matter of months or a couple growing seasons. The sympathetic Californians who voted for legalization out of compassion for various sufferers who claimed they needed the pain-suppressing attibutes of marijuana, how could they be so short-sighted and deluded not to think they were not voting all America into forced acceptance of the drug and, consequently, enslavement to the drug-culture of hard-line drugs like crack and heroin that initial use of marijuana most often leads to? God help us, if this happens, but what is to stop it? Is this the final blow to America as a free and prosperous nation? How can California's shaken economy continue to recover, and how can the people of California operate as a society without completely collapsing? The gates have been burst wide open to the most destructive addictions and obsessions and delusional thinking--and now all the enemy has to do is walk right in, for there can be no resistance.--Ed.

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