One of the most common pieces of folk wisdom regarding cannabis is that it causes schizophrenia. For some reason, the one thing that every muggle seems to know about cannabis is that, if you smoke too much of it, you go crazy. Like almost everything else that muggles think they know about cannabis, this factoid is bollocks, as this examination will show.
The reason why it is commonly believed that cannabis causes schizophrenia is because of the large number of schizophrenics who smoke cannabis. It is believed that up to 25% of schizophrenics have a “cannabis use disorder”, and there is certainly a strong association between the two, but it isn’t because cannabis causes psychosis.
Most schizophrenics could have told you many years ago (as we did in the Cannabis Activist’s Handbook) that cannabis is medicinal for people with mental illnesses. There is currently much interest in the use of CBD (cannabidiol) medicine in the treatment of psychosis. This is also mentioned here. A Schizophrenia Bulletin article stated that “Interest in the therapeutic potential of CBD stemmed from evidence that it has broadly opposite effects to that of THC.”
The most recent evidence suggests that cannabidiol has the opposite effect of THC in many ways. CBD appears to reduce positive symptoms (e.g. hallucinations) in schizophrenics, which again testifies to its medicinal qualities. It doesn’t cause them – indeed, “even high doses of oral CBD do not cause psychological, psychomotor, cognitive, or physical effects that are characteristic for THC.”
This recent research suggests that some of the cannabinoids in the cannabis plant, particularly CBD, have a calming and soothing effect. This effect is not necessarily limited to people with mental illnesses, but for people with mental illnesses this calming and soothing effect is certainly medicinal. Once the medicinal benefits of CBD are understood, it becomes obvious that much of the reason for the association between psychosis and cannabis is because psychotics find that ingesting the CBD in cannabis alleviates some of the suffering that comes with psychosis.
This study found that it was much more likely that predictors of schizophrenia led to cannabis use than that cannabis use led to schizophrenia; in other words, underlying factors that tended to cause schizophrenia also tended to cause cannabis use. Of some interest is that schizophrenia itself is a predictor of future cannabis use, which supports the idea that the nature of the suffering caused by the condition happens to be alleviated by cannabis. Indeed, cannabis use itself is a heritable trait.
Supporting this was a study that found that “cannabis use was genetically correlated with a wide range of behaviors and personality traits, such as alcohol use and dependence, increased risk taking, and decreased conscientiousness, as well as a variety of mental health disorders.”
So there is mounting evidence that underlying psychological factors explain much of the cannabis-psychosis connection. It’s known that genes heavily influence many personality traits, such as openness and degree of neophilia/neophobia, and it’s likely that such qualities lead naturally to both schizophrenia and to cannabis use. Personality characteristics that correlate with developing schizophrenia also correlate with future cannabis use.
Yet another study found that executive function in schizophrenics was superior if they were cannabis users. Examples of executive function are problem solving, working memory and cognitive flexibility. This ties in with the argument, made at length elsewhere (such as here), that the use of cannabis keeps the mind young and plastic. This may be especially true in the case of schizophrenics because of possible neurodegenerative effects of schizophrenia.
Many schizophrenics are able to tell you that cannabis grants the ability to set aside certain recurring thought patterns, particularly those of the brooding or obsessive variety. It is often possible to get stuck in thought loops and ruminate if one does not have a substance that facilitates novel and original thought patterns. Something about the nature of schizophrenia makes brooding and obsessive thoughts more likely, and so it’s apparent that a substance with the effects mentioned in the studies above will be of benefit to schizophrenics, and that this will cause them to use it more.
So the reality is that cannabis does not cause schizophrenia, but that factors associated with schizophrenia are also associated with cannabis use, and these underlying reasons are why schizophrenics use so much cannabis. In particular, a certain kind of mind has qualities that make then prone to both developing a cannabis habit and developing schizophrenia. We can guess at what some of these qualities are: no doubt openness and creativity are at the forefront, as is an early childhood marked by abuse and neglect.
Most crucially, it’s now more apparent than ever that cannabidiol is highly medicinal for people with schizophrenia. This is the main reason for the association between schizophrenia and cannabis use – using cannabis brings relief from the suffering that comes with conditions like schizophrenia. People with schizophrenia have long known this, which is why they continue to use it at high rates despite intense discouragement from doctors and politicians.
Not only is the argument that cannabis causes schizophrenia false, but the opposite is true. Elements of the cannabis plant act as anti-psychotics that alleviate the symptoms of psychotic disorders. Cannabis should be made legal so that those who benefit from the anxiolytic and antipsychotic properties of, e.g., cannabidiol, can get access to it for the sake of alleviating the suffering associated with their condition. This is especially true for schizophrenics, who seem to benefit greatly from CBD medicine.
This article is an excerpt from The Case For Cannabis Law Reform, compiled by Vince McLeod and due for release by VJM Publishing in the summer of 2018/19.