Genetic Overlap between Cannabis Use and Schizophrenia

A new study has added to the belief that schizophrenia increases the chances of a sufferer to smoke weed. Researchers said that a person's likelihood to smoke pot can also be predicted through his genetic variants predicting schizophrenia, regardless of the mental health history.

The study has raised questions over the certainty of a causal relationship between cannabis use and schizophrenia. The results showed that a small part of the association might be caused by genetic overlap. It means, the same genes that are responsible to predispose certain people to use pots are also likely to predispose others to develop schizophrenia - or both.

The researchers studied genetic data from recently published studies of schizophrenia and identified genetic variants responsible for causing the disease. After this, they used the information on a random sample of about 2,000 healthy Australians to identify if those variants are capable of predicting cannabis use.

"There is a well-established link between people who use cannabis and schizophrenia. But this study indicates that people who are at risk for schizophrenia are more likely to use cannabis, and in greater quantities", said Robert Power, lead author of the study and a genetic psychiatrist at King's College London. So, it wouldn't be wrong to say that the causal relationship could be applied both ways.

Also, the genetic variants associated with schizophrenia predicted cannabis use in healthy individuals, therefore some genetic overlap between the two is a high possibility.

The study has provided very important results, said Eden Evins, a psychiatry professor at Harvard University. She added that increased genetic risk for developing schizophrenia increased the likelihood of one to use cannabis and the use could be heavy. But she did not deny the previous findings that cannabis use increases the risk of developing schizophrenia and perhaps both are true.