A new study finds that the same gene may be responsible for increasing the risk of schizophrenia and marijuana addiction.
The study was conducted by researchers from the King's College London. About 2,082 healthy participants took part in the study. Among these, 1,011 reported using cannabis. Researchers first made note of each participant's "genetic risk profile" - which is the number of genes that is associated with schizophrenia. The researchers found that people genetically pre-disposed to schizophrenia were more likely to use cannabis, and use it in greater quantities than those who did not possess schizophrenia risk genes. The findings confirm previously found links between schizophrenia and marijuana use.
"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," Robert Power, lead author from the Institute of Psychiatry at King's said in a press statement.
A 2013 survey by the National Survey on Drug Use and Health found that more than 7 percent of Americans aged 12 and above used marijuana the previous year, a number that was only 5.8 percent in 2007, according to USA Today.
"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," Power said.
Earlier this week, the state of New York legalized the use of marijuana for medical purposes, becoming the 23rd states in the United States where cannabis has been legalized for therapeutic purposes. Under the new bill, the Health Department would license five private companies in the state to produce and distribute medical marijuana products through dispensaries, according to Reuters.
The study was funded by the National Institutes of Health, Australian National health and Medical Research Council, Australian Research Council, GenomEUtwin Project, Centre for Research Excellence on Suicide Prevention in Australia, the National Institute for Health Research Biomedical Research Centre (NIHR BRC) at the South London and Maudsley NHS Foundation Trust and King's College London and the Netherlands Organization for Health Research and Development.
Findings were published online in the journal Molecular Psychiatry.
