Is Reefer Madness real? While past studies have shown a connection between marijuana use and schizophrenia it has never been clear whether marijuana use actually increases the risk of becoming schizophrenic.
A new study just published in Molecular Psychiatry has revealed more about this relationship. The research project was a collaborative effort between King’s and Queensland Institute of Medical Research in Australia. It was funded, in part, by the UK MRC (Medical Research Council.)
Marijuana has long been known as the most commonly-used illegal drug in the world. Additionally, it is reportedly used more among individuals “with schizophrenia than in the general population.” Statistically-speaking, schizophrenia is said to affect about 1 in 100 people and marijuana users are approximately twice as likely to develop the mental disorder.
Common symptoms of schizophrenia include hearing voices (auditory hallucinations) and false beliefs (delusions). The specific cause remains a mystery and yet studies have demonstrated that a mixture of environmental, genetic, physical and psychological factors can cause a person to develop the disorder. Prior research has discovered different genetic risk variants related to schizophrenia, each of which increases a person’s risk of becoming schizophrenic.
Lead Author Mr. Robert Power of the MRC Social, Genetic and Developmental Psychiatry (SGDP) Centre at the Institute of Psychiatry at King’s College, London, England said: “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.”
Power and company examined 2,082 healthy participants out of which 1,011 had used marijuana. They measured each person’s “genetic risk profile” to determine the specific number of genes associated with schizophrenia that they each carried. The study results revealed that participants who were “genetically pre-disposed to schizophrenia” were significantly more likely to use marijuana. They were also more likely to use it in larger quantities that those who did not carry any “schizophrenia risk genes.”
Jack S. Chesney, former Penn State penman and marijuana aficionado noted: “While I’ve obviously not been involved with this study I have been following related research since college. I knew a doctoral candidate who had similar beliefs but he was more concerned with the frequency of this actually becoming a statistically-relevant issue. For what it does we all expected it to have some effect but the question is how significant are all these various effects and how much must one smoke before it becomes a relevant concern?”
Power stated: “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.”
He 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.”