DEBUNKED: Cannabis does NOT cause schizophrenia

It’s not unusual to hear those who are opposed to legalizing cannabis claim that it can cause people to develop mental illnesses like schizophrenia, but new research shows that there is very little truth behind the notion.

According to King’s College London Psychology Research fellow Dr. Musa Sami, there is no direct correlation between cannabis use and the development of schizophrenia. He points out that if a link did exist, schizophrenia diagnoses in the U.K. would be rising given the increasing potency of THC in street cannabis, but that is simply not the case.

Dr. Sami said that while cannabis use is common, schizophrenia remains relatively rare. In fact, it affects less than one percent of the population, while 6.2 percent of those in the U.K. are believed to be cannabis users.

As part of his research, Dr. Sami surveyed 1,231 cannabis users to find out more about their experiences in terms of enjoyment as well as psychosis. He found that those who had the most enjoyable experiences with it say they have no intention of quitting the drug, while those who experience more psychotic-like experiences were either thinking of quitting eventually or had already stopped. Indeed, he found that it was this experience that determined whether or not a person kept using it rather than their sex, age, history of mental health, or other drug use.

He said this could mean that those who have the highest risk are the ones who are actually quitting the drug, thereby possibly offsetting their risk of developing the illness from cannabis use.

Dr. Sami says further research is needed in the matter. He said he’d like to see a long-term study that maps people’s cannabis experiences and their risk of schizophrenia, although he concedes it would be a lengthy and costly study to carry out.

Past research shows connection is strongest in those with genetic predisposition to schizophrenia

Past studies have pointed to a more complex connection between schizophrenia and cannabis use. According to research from Tel Aviv University that was published in the Human Molecular Genetics journal, cannabis use is most likely to cause long-term psychiatric effects in the people who are most susceptible to such problems. For example, those with a genetic susceptibility to schizophrenia due to a family history of the illness should be cautious around marijuana, particularly in adolescence. So while cannabis use might raise psychosis risk in some people, the effects can be considered relatively small across the population.

Schizophrenia is a serious mental disorder that affects the way in which a person behaves, feels and thinks. People suffering from this ailment may appear to have lost touch with reality. It typically starts between the ages of 16 and 30, which overlaps somewhat with the ages that people typically try marijuana for the first time.

Symptoms might include delusions, thought disorders, movement disorders and hallucinations. Sufferers might also report reduced pleasure in daily life, reduced speaking, working memory problems, and trouble starting and sustaining activities.

The disease can sometimes run in families, but researchers don’t think a single gene is responsible for causing the disorder. Instead, they believe that different genes can raise the risk of schizophrenia. They also believe that interactions between the genes and certain aspects of a person’s environment are required for schizophrenia to develop. These environmental factors might involve problems or malnutrition before or during birth, psychosocial factors, and exposure to viruses.

While those who are most susceptible to schizophrenia might want to be careful when it comes to cannabis, it appears that most people don’t have much to worry about.

Sources for this article include:

MedicalMarijuana.co.uk

MedicalNewsToday.com

TheConversation.com

NIMH.NIH.gov