There has been quite a bit of research done on the link between marijuana and a higher potential for psychosis, although most have focused on patients who have a genetic predisposition to a psychotic disorder and an earlier onset of that disorder. There is also a question of higher THC level products being the main concern, and altogether, lots more research should be done before our understanding is fully fleshed out.
So add this study to the batch of an extremely complex relationship. A new study that combined researchers at Zucker Hillside Hospital, Stanford University, University of Michigan, and University of California at Davis was published that shows that over a two year period, regular use of marijuana for a group of young adults that had a risk of developing psychotic disorders did NOT cause any early onset of symptoms. And more so, the weed smoking was associated with improved cognitive functioning and a reduction of other medication use.
The study tracked 210 clinical high risk individuals who smoked marijuana and compared their behavior to other clinical high risk individuals who did not smoke marijuana.
Ultimately, the study found that “continuous cannabis use over 2-years of follow-up was not associated with an increased psychosis transition rate, and did not worsen clinical symptoms, functioning levels, or overall neurocognition. Nevertheless, our findings suggest that continuously using cannabis may be associated with slightly elevated, albeit non-significant, attenuated positive symptom levels relative to non-users.”
Marijuana-users had “higher neurocognition and social functioning over time, and decreased medication usage, relative to non-uers. Surprisingly, clinical symptoms improved over time despite the medication decreases.”
This study adds to the nuance of the link between psychosis and marijuana, and points to much more need for further research. However, this study is certainly a good direction to be headed.