Psychiatric comorbidity associated with synthetic cannabinoid use compared to cannabis

J Psychopharmacol. 2016 Dec;30(12):1321-1330. doi: 10.1177/0269881116658990. Epub 2016 Jul 26.


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.

Keywords: K2; Spice; Synthetic cannabinoids; agitation; cannabis; psychosis.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cannabinoids / adverse effects*
  • Cannabis / adverse effects*
  • Comorbidity
  • Female
  • Humans
  • Male
  • Marijuana Abuse / epidemiology
  • Marijuana Abuse / etiology
  • Psychoses, Substance-Induced / epidemiology*
  • Psychoses, Substance-Induced / etiology*
  • Psychotic Disorders / epidemiology*
  • Psychotic Disorders / etiology*
  • Retrospective Studies
  • Substance-Related Disorders / epidemiology
  • Substance-Related Disorders / etiology


  • Cannabinoids