Pot and schizophrenia? Madness and reefer? It’s all in the genes. A new study is linking the use of pot with schizophrenia, but it’s not what you think. While previous studies have attempted to establish a causal relationship between smoking up and developing neurotic phobias, a new study is flipping the reefer equation. It’s no longer a one-way street.
Explains NBC News: “Genes that increase the risk of a person developing schizophrenia may also increase the chance they will use cannabis, researchers said on Tuesday after studying more than 1,000 users of the drug. The results chime with previous studies linking schizophrenia and cannabis, but suggest the association may be due to common genes and might not be a causal relationship where cannabis use leads to increased schizophrenia risk.”
Pot is used by more people in the world than any other drug, and peer-reviewed studies have already established that prolonged cannabis use is a factor in individuals developing psychoses.
Robert Power, study leader from the Institute of Psychiatry at King's College London, said that it’s also equally likely that a person that already suffers from schizophrenia may turn to marijuana.
“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 predisposition to schizophrenia also increases your likelihood of cannabis use,” Power said.
In other words, the slant on causation has been rotated, and genetic disposition is in itself a risk factor for turning to pot. These shared genetic markers may explain the elevated marijuana use among those diagnosed with schizophrenia, and also may muddy the waters of previous studies and influence current debates as more states look to change their stance on legalizing marijuana for medical and or recreational use.
The European study was published online Tuesday in the journal Molecular Psychiatry.
The Los Angeles Times explains the study:
Researchers studied 2,082 people, about 49 percent of who reported having smoked pot. They analyzed the participants’ genome, looking for known variations that have been associated with schizophrenia. They found that those with the strongest genetic profile for schizophrenia risk also were more likely to use cannabis, and to use it in greater quantities.
So while the exact nature of the relationship between schizophrenia and pot is yet unclear, the study showed that regardless of mental health history, those with a predisposition to developing schizophrenia, as defined by their genes, were more likely to use cannabis than the individuals in the study that lacked schizophrenia-triggering genetics.
Our understanding of mental illness and pot smoking has been evolving. In the 60s, scientists concluded that smoking marijuana was a direct factor in psychosis. Now, researchers are backing off that posture some and showing that pot use may spur schizophrenia, but generally only in those that already have a predisposition to its use.
Power said their study "highlights the complex interactions between genes and environments” when it comes to the colloquial link between the two. "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,” he said.