Early onset of cannabis use and violent behavior in psychosis
Valérie M. Moulin, Luis Alameda, David Framorando, Philipp-S Baumann, Mehdi Gholam, Jacques Gasser, Q. Kim, Philippe Conus
European Psychiatry 2020 DOI: 10.1192/j.eurpsy.2020.71 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 265 |
| Population | Early psychosis patients aged 18-35 years |
| Duration | 36-month follow-up |
| Topics | Cannabis |
| Citations | 22 |
| Key findings | Among 265 early-psychosis patients followed for 36 months, 72 displayed violent behavior. Those who were violent had started using cannabis at an average age of 15.29 versus 16.97 for nonviolent patients, and cannabis use onset by age 15 was associated with higher odds of later violence (odds ratio 4.47, CI 1.13-20.06) after adjustment. The authors suggest early cannabis use may play a role in the emergence of violent behavior in early psychosis. |
Abstract
Background: Although evidence from psychosis patients demonstrates the adverse effects of cannabis use (CU) at a young age and that the rate of CU is high in subgroups of young violent patients with psychotic disorders, little is known about the possible effect of the age of onset of CU on later violent behaviors (VB). So, we aimed to explore the impact of age at onset of CU on the risk of displaying VB in a cohort of early psychosis patients.
Method: Data were collected prospectively over a 36-month period in the context of an early psychosis cohort study. A total of 265 patients, aged 18-35 years, were included in the study. Logistic regression was performed to assess the link between age of onset of substance use and VB.
Results: Among the 265 patients, 72 had displayed VB and 193 had not. While violent patients began using cannabis on average at age 15.29 (0.45), nonviolent patients had started on average at age 16.97 (0.35) (p = 0.004). Early-onset CU (up to age 15) was a risk factor for VB (odds ratio = 4.47, confidence interval [CI]: 1.13-20.06) when the model was adjusted for age group, other types of substance use, being a user or a nonuser and various violence risk factors and covariates. History of violence and early CU (until 15) were the two main risk factors for VB.
Conclusions: Our results suggest that early-onset CU may play a role in the emergence of VB in early psychosis.
Comparable studies
Other observational and cohort studies on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| High-potency cannabis and the risk of psychosis People with first episode of psychosis and healthy controls from the local population | 2009 | Case-control study | n = 454 |
| Ayahuasca-Assisted Therapy for Addiction: Results from a Preliminary Observational Study in Canada Rural aboriginal population | 2013 | Observational study | |
| Impaired cognitive performance in drug free users of recreational ecstasy (MDMA) Otherwise healthy young people | 2000 | Observational | |
| Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study Individuals from the general population in Germany aged 14-24 at baseline | 2011 | Observational cohort | n = 1,923 |
| Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases Patients treated for cannabis-induced psychotic symptoms in Denmark between 1994 and... | 2005 | Observational cohort | n = 535 |