Differential effects of cannabis exposure during early versus later adolescence on the expression of psychosis in homeless and precariously housed adults.
K. Gicas, Alex Y T Cheng, William J. Panenka, David D. Kim, Jade C Yau, R. Procyshyn, Jacob L. Stubbs, Andrea A. Jones, Simran Bains, A. Thornton, D. Lang, A. Vertinsky, A. Rauscher, William G. Honer, Alasdair M. Barr
Progress in Neuro-Psychopharmacology and Biological Psychiatry September 2, 2020 DOI: 10.1016/j.pnpbp.2020.110084 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Longitudinal Peer reviewed |
|---|---|
| Sample size | 437 |
| Population | Homeless and precariously housed adults from single room occupancy hotels in Vancouver, Canada |
| Topics | Cannabis |
| Key findings | Early cannabis exposure (by age 15) increased risk of substance-induced psychosis, while later first use increased risk of schizophrenia or schizoaffective disorder. |
Abstract
Longitudinal studies of cannabis exposure during early adolescence in the general population frequently report an increased risk of subsequently developing psychotic symptoms or a psychotic illness. However, there is a dearth of knowledge about the effects of early cannabis exposure on psychosis in homeless and precariously housed adults, who represent a population afflicted with high rates of psychosis. The aim of the present study was to examine how early cannabis exposure (by age 15) compared to later first use (after age 15) affected the expression of adult psychosis in this population. Secondary measures of psychopathology, drug use, cognition and brain structure were also collected. 437 subjects were recruited from single room occupancy hotels in the urban setting of the Downtown Eastside of Vancouver, Canada. Psychiatric diagnoses were determined, and psychotic symptom severity was measured with the 5-factor PANSS. Participants completed a battery of neurocognitive tests, and brain structure was assessed using structural and diffusion tensor imaging MRI scans. Results indicated that early cannabis exposure was associated with an increased risk (OR = 1.09, p < .05) of developing substance induced psychosis, whereas later first use increased risk (OR = 2.19, p < .01) of developing schizophrenia or schizoaffective disorder. There was no group difference in neurocognitive function, although differences were observed in the lateral orbitofrontal cortex and white matter tract diffusivity. These findings indicate that early cannabis exposure in this population may increase the risk of developing drug associated psychoses, which could potentially be mediated in part through altered neurodevelopmental brain changes.
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 |
Citations in the library
Cites 7
- Age-related differences in the impact of cannabis use on the brain and cognition: a systematic review European Archives of Psychiatry and Clinical Neuroscience January 24, 2019
- Adolescent exposure to Δ9-tetrahydrocannabinol alters the transcriptional trajectory and dendritic architecture of prefrontal pyramidal neurons. Molecular Psychiatry April 2019
- Marijuana Matters: Reviewing the Impact of Marijuana on Cognition, Brain Structure and Function, & Exploring Policy Implications and Barriers to Research International Review of Psychiatry May 4, 2018
- Evidence for the Risks and Consequences of Adolescent Cannabis Exposure. Journal of the American Academy of Child & Adolescent Psychiatry March 2017
- Adolescent Cannabinoid Exposure Induces a Persistent Sub-Cortical Hyper-Dopaminergic State and Associated Molecular Adaptations in the Prefrontal Cortex. Cerebral Cortex February 1, 2017
and 2 more in the library