Remember the pot-smoking teens turned violent hooligans from the 1930s cult classic Reefer Madness? A completely goofy and obviously exaggerated bit of movie hysteria? For sure. A real-life look at the effects of marijuana on the brain? Well, maybe that too. Turns out, the drug could cause serious and irreparable damage, and even changes that resemble schizophrenia, according to a new study published in Schizophrenia Bulletin.
Using MRI scans from the brains of young men who smoked marijuana heavily as teenagers, scientists at Northwestern University's Feinberg School of Medicine discovered two things:
First, they found that the former pot smokers, now in their early twenties, had developed “abnormalities” in regions of the brain associated with short-term memory. More specifically, the thalamus, the "Grand Central Station" of neuro-information, was oddly shaped among study subjects. “Both of the groups [we studied] that had a history of marijuana use demonstrated reduced or impaired performance on memory tasks," notes lead study author Matthew Smith, Ph.D.
Second, and perhaps more shocking, they found that the abnormally shaped brains looked like brains damaged by schizophrenia. For pot smokers already diagnosed with the mental disorder, damage to the thalamus seemed even more severe, perhaps making the illness all the more profound.
Does this mean that smoking weed could lead to mental illness? Not necessarily. Smith cautions against such extreme conclusions and tells us that more research is needed to hash out the long-term effects of marijuana. However, there are a few key things to take away from his research. First, smoking will affect your short-term memory, possibly limiting your ability to process information. This could lead to poor performance at work or school, and might also limit your ability to retain information long-term. Second, marijuana could exaggerate your susceptibility to mental illness: “If you have a family history of schizophrenia and you chronically use marijuana, your risk for developing schizophrenia goes up," says Smith.