Individuals who consume cannabis alone, rather than in the company of others, are twice as likely to screen positive for psychosis. The findings were part of March 2019 study from Dalhousie University published in Drug and Alcohol Review.
The study also found that lone smokers are more likely to use the drug to cope with stress, consume more often than social smokers, and show symptoms of dependence.
Researchers looked at data collected in 188 adults in 2011 interviews at Dalhousie, with participants ranging in age from 18 to 59. Subjects were recruited from the Halifax area and were 44 percent female. Participants were asked about various psychiatric symptoms, their motives for using the drug, and to describe the last time they consumed cannabis.
Researchers note that study results do not indicate that cannabis use is the cause of the psychosis, but that there is a correlation between the two. iStock / Getty Images Plus
Psychology and neuroscience master’s student Toni Spinella co-authored the study with Drs. Sean Barrett and Sherry Stewart, her supervisor and an addiction specialist and clinical psychologist, respectively.
“It’s possible that they lack other coping strategies,” Spinella told CBC. “If you’re alone, why are you using alone? That’s something that you might want to ask yourself and if you realize, ‘OK, I’m using alone because I’m sad tonight or I’m stressed,’ then maybe that’s a red flag that you should think more about.”
People who use cannabis alone are also more likely to use it more frequently, reporting use during 25 days of the month, as opposed to an average of 12 days for social smokers, although the latter was approximately three times more likely to consume alcohol alongside cannabis.
Researchers note that study results do not indicate that cannabis use is the cause of the psychosis, but that there is a correlation between the two. They found no correlation between diagnoses of psychiatric disorders and the social context of consumers’ cannabis consumption.
Spinella stresses that further research is needed.