Does cannabis lead to schizophrenia or do schizophrenics often use cannabis?
Researchers are now trying to better understand the connection between schizophrenia and cannabis. In their investigation, they found that there is strong evidence that cannabis is used as a form of self-therapy in many patients with schizophrenia. So far, doctors have believed that cannabis abuse leads to schizophrenia. Now the situation is very different.
Scientists at the University of Bristol found in an investigation that patients with schizophrenia often use cannabis as a form of self-therapy. For a long time, doctors had believed that cannabis increased the risk of schizophrenia. The doctors have now published the conflicting results of their study in the journal Psychological Medicine.
Schizophrenic people often smoke cannabis
Cannabis users are at increased risk of developing schizophrenia, doctors say. However, the causal relationship has so far remained unclear. The new study found that people with schizophrenia are more likely to use cannabis. "There was strong evidence of a causal effect of schizophrenia on the likelihood of cannabis initiation," the doctors explain.
Highly potent cannabis strains are particularly dangerous
There have been warnings for some time that cannabis users are at increased risk of developing psychosis. Cannabis strains with a high THC content appear to be at increased risk, experts say. These varieties have recently been used increasingly by young people and are colloquially often referred to as skunk.
Cannabis risks should not be exaggerated
However, the experts point out that the risks of cannabis should not be exaggerated. A closer examination of the links between mental health and illegal drugs is needed beforehand. The current study from Bristol sheds new light on this topic. "Nevertheless, the wider context of the other mental health factors must be taken into account in the results," the authors explain.
Schizophrenic people use cannabis for self-medication
Indeed, there was some evidence to support hypotheses that cannabis use contributed to increasing the risk of schizophrenia. It was surprising, however, that stronger evidence was found that schizophrenic people are more likely to use cannabis. Cannabis could actually be used as a form of self-medication for patients with schizophrenia, the scientists add.
Study used research on genetic variants
A new research technique was used for the study. This used genetic variants to investigate the risk of cannabis and the risk of developing schizophrenia. The technique has been used as an alternative to conventional observation epidemiology. This makes it possible to consider other variants that could influence the association, the researchers explain.
Heavy cannabis abuse leads to the greatest risk of schizophrenia
There was also some evidence of a causal effect of cannabis initiation on the risk of schizophrenia, the authors explain in the study. However, the evidence was significantly stronger for the causal effect of schizophrenia on the likelihood of cannabis initiation, the experts add. High cannabis use appears to be most associated with the risk of schizophrenia. The evidence suggests that an existing risk of schizophrenia increases the likelihood of using cannabis. However, the relationship could work in both directions, explains author Dr. Suzi Gage. “Our results don't really allow us to accurately predict the size of the effect. However, they can provide evidence that the relationship is actually causal and not the result of common risk factors, ”added Dr. Gage added.
More research is needed
While we have found stronger evidence that the risk of schizophrenia affects cannabis use than vice versa, this does not rule out a causal risk of using cannabis for the development of schizophrenia, the doctor says. A real advance in research would be to use genetic variants to predict the severity of cannabis use. It currently seems that whether serious cannabis abuse is most associated with the risk of developing schizophrenia. (as)