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Schizophrenia risk and marijuana use might be linked, a new study reported. According to a research team headed by King's College London, people who carry genes that indicate an increased risk of developing schizophrenia also have a higher risk of using cannabis.

"Studies have consistently shown a link between cannabis use and schizophrenia. We wanted to explore whether this is because of a direct cause and effect, or whether there may be shared genes which predispose individuals to both cannabis use and schizophrenia," Robert Power, lead author from the Institute of Psychiatry at King's, stated according to the press release.

For this study, Power and researchers from Queensland Institute of Medical Research located in Australia, examined 2,082 healthy participants. 1,011 of them reported using cannabis. The researchers analyzed each participant's "genetic risk profile," which looked for the total number of schizophrenia risk genes. The team found that participants who carried more schizophrenia risk genes were more likely to use cannabis in comparison to those who did not have schizophrenia risk genes.

"We know that cannabis increases the risk of schizophrenia. Our study certainly does not rule this out, but it suggests that there is likely to be an association in the other direction as well - that a pre-disposition to schizophrenia also increases your likelihood of cannabis use," Power concluded. "Our study highlights the complex interactions between genes and environments when we talk about cannabis as a risk factor for schizophrenia. Certain environmental risks, such as cannabis use, may be more likely given an individual's innate behavior and personality, itself influenced by their genetic make-up. This is an important finding to consider when calculating the economic and health impact of cannabis."

The study, "Genetic predisposition to schizophrenia associated with increased use of cannabis," was published in Molecular Psychiatry.