Psychiatric comorbidity associated with synthetic cannabinoid use compared to cannabis

Background: Synthetic cannabinoids (SC) use has had a dramatic increase in recent years, but data regarding their adverse effects on mental health is limited. In this study, we compared clinical presentations of SC users with cannabis users in a psychiatric inpatient setting. Methods: Digital charts of all patients who were admitted to a dual diagnosis psychiatric unit in one year were reviewed. Patients who had any current substance use disorder were categorized in four groups: (1) SC use and cannabis use (SC+MJ+), (2) SC use without cannabis use (SC+MJ-), (3) cannabis use without SC use (SC-MJ+), and (4) No SC or cannabis use (SC-MJ-). Results: A total of 594 charts were included. SC+MJ- patients had significantly more psychotic symptoms (OR: 4.44, 95% CI: 1.98-9.94), followed by SC+MJ+ (OR: 3.61, 95% CI: 1.87-6.97) and SC-MJ+ (OR: 1.87, 95%CI: 1.33-2.64) patients. The SC+MJ- group also had more agitation and aggression was most prominent in SC+MJ+ subjects. Multivariate analyses showed that the psychiatric associations of SC and cannabis use remained significant even after controlling for potential confounds such as other substance use. Conclusions: The prominent psychiatric features of SC users as compared to cannabis users in an inpatient setting are psychotic presentations and agitation, which have important treatment implications.