Does Long-Term Marijuana Use Lead To Mental Illness?

By John Lavitt 03/03/16

Multiple studies have linked marijuana to psychosis, but the direct relation is far more complex. 

Does Long-Term Marijuana Use Lead To Mental Illness?
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Although a connection between chronic cannabis use and depression has been apparent for some time, the more concerning relationship between long-term marijuana use and the onset of chronic psychosis is just now being highlighted. As more and more local governments jump on board the pot bandwagon, the National Institute on Drug Abuse has reported on the drug's potential long-term negative effects, citing several studies in 2015 that found links to long-term mental health issues and smoking marijuana—though the agency recognizes the plant's therapeutic benefits as well.

"There are several ways to explain the link between cannabis use and psychosis, and a causal relationship has not yet been firmly established," Joseph M. Pierre, co-chief of the Schizophrenia Treatment Unit at the Veterans Administration West Los Angeles Healthcare Center, wrote in a 2011 report. "Current evidence supports that cannabis is a 'component cause' of chronic psychosis, meaning although neither necessary nor sufficient, cannabis use at a young age increases the likelihood of developing schizophrenia or other psychotic disorders."

The relationship between marijuana and mental illness is surely complex. Mental illness is bred from a plethora of other factors that contribute to an individual developing such issues. For some, these factors can be related directly to the cannabis use itself—like how young the individual was when they first started smoking and the frequency of use. 

The NIDA noted last year that there seems to be a genetic predisposition to developing such symptoms in the first place. "Recent research has found that marijuana users who carry a specific variant of the AKT1 gene … are at increased risk of developing psychosis," wrote the NIDA. "One study found that the risk for those with this variant was seven times higher for daily marijuana users compared with infrequent- or non-users." 

Despite such studies that suggest a link between marijuana and mental illness, researchers still cannot prove the connection on a scientific level. Although you're more predisposed to develop mental health issues if you possess the specific type of the AKT1 gene, there's clearly no need to believe that smoking marijuana itself will drive you crazy. As Pierre explained, “The overall magnitude of risk appears to be modest, and cannabis use is only one of myriad factors that increase the risk of psychosis. Furthermore, most cannabis users do not develop psychosis."

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Growing up in Manhattan as a stutterer, John Lavitt discovered that writing was the best way to express himself when the words would not come. After graduating with honors from Brown University, he lived on the Greek island of Patmos, studying with his mentor, the late American poet Robert Lax. As a writer, John’s published work includes three articles in Chicken Soup For The Soul volumes and poems in multiple poetry journals and compilations. Active in recovery, John has been the Treatment Professional News Editor for The Fix. Since 2015, he has published over 500 articles on the addiction and recovery news website. Today, he lives in Los Angeles, trying his best to be happy and creative. Find John on Facebook, Twitter, and LinkedIn.