A team of researchers from Canada and Italy conducted this study to explore the links between substance use disorders and violence in patients diagnosed with schizophrenia spectrum disorders. This retrospective study, recently published in the Journal of Clinical Psychopharmacology, attempted to unravel “whether cannabis use disorder is associated with violent and/or psychotic behavior in patients who are hospitalized in a high-security hospital.”
The researchers conducted the study using data from 124 patients diagnosed with schizophrenia or other psychotic disorders. All subjects had been admitted to a high-security mental health facility due to their history of violent behavior. Researchers assessed each subject's lifetime history of violence, impulsivity, and substance abuse using standard psychiatric surveys.
The study reports that violent psychotic patients were just as likely to use cannabis as nonviolent patients diagnosed with similar conditions. Violent subjects were far more likely to have abused alcohol and cocaine than nonviolent patients, however. Researchers also found that cannabis use was not linked to increases in impulsivity, but alcohol users were more likely to commit impulsive thoughtless gestures.
A final logistic regression analysis of the data revealed that alcohol use disorder was strongly associated with a lifetime history of violence, but cannabis and cocaine use were not linked to increased violent behavior.
“These findings show that cannabis and alcohol are largely abused and coabused by psychotic patients with a propensity for violence, but only alcohol is associated with impulsive and violent behavior,” the study authors concluded. “Therefore, especially alcohol abuse should be seriously considered by practitioners when evaluating the dangerousness of patients with schizophrenia spectrum disorders.”
The findings of this study help dispel myths that cannabis use increases the risks of violent or psychotic behavior. Older studies have discovered correlations between pot and psychosis, and some traditional researchers have interpreted these findings to suggest that weed directly causes psychosis. Newer, more focused studies have cast serious doubt on these speculations, though. Researchers now believe that the most plausible explanation for these correlations is that people with schizophrenia or other mental health issues are more likely to use cannabis as a form of self-medication.
In fact, some cannabinoids may actually have antipsychotic properties. Although there is evidence that THC can increase anxiety or symptoms of psychosis, new research has found that CBD can actually reduce these symptoms.
Another new study also reports that cannabis strains that contain equal ratios of THC and CBD are less likely to cause anxiety or other negative feelings, which could help explain why people suffering from schizophrenia or related disorders may deliberately seek out cannabis to help alleviate these symptoms.