Joint-trajectories of clinical severity, social functioning and cannabis use in first-episode psychosis: A 5-year longitudinal study in 2 urban early intervention services.
Giuseppe D'Andrea, Clairélaine Ouellet-Plamondon, Marie Villeneuve, Jai L Shah, Srividya N. Iyer, A. Abdel-Baki
Psychiatry Research September 1, 2024 DOI: 10.1016/j.psychres.2024.116184 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Longitudinal cohort study Peer reviewed |
|---|---|
| Sample size | 395 |
| Population | Incident first-episode psychosis (FEP) cases |
| Duration | 5-year follow-up |
| Topics | Cannabis |
| Key findings | Five joint-trajectories of cannabis use, clinical severity, and social functioning were identified over five years. Groups that stopped or reduced cannabis use improved clinically, while continued users showed no significant improvement and had higher odds of homelessness (OR 22.5) and childhood adversity (OR 2.25). The authors argue for cannabis-reduction and trauma-informed interventions. |
Abstract
Cannabis use is associated with increased psychosis incidence alongside worse outcomes. The role of cannabis may be complex, vary across patients and over time. Yet, few have examined the longer-term trajectories of cannabis use, symptoms and functioning and their inter-relationships. We conducted a 5-year longitudinal study to estimate joint-trajectories of clinical severity, social functioning, and cannabis use via group-based multi-trajectory modelling on a sample of 395 incident FEP cases. Associations of trajectories with socio-demographic and clinical factors were tested using multinomial regression. The best-fitting model identified 5 joint-trajectories. A first group (N = 93,23.7 %) presented only marginal improvement despite not using cannabis, while a second with no cannabis use and a third group with low-decreasing use showed clinical amelioration. Among those with baseline harmful cannabis use, a fourth group progressively discontinued use and improved clinically (N = 78,19.9 %). A fifth group with continued use did not significantly improve over follow-up (N = 74,18.8 %), and also had the highest odds of homelessness (OR = 22.5,95 %CI = 6.25-81.1) and childhood adversities (OR = 2.25,95 %CI = 1.71-2.97). There is substantial heterogeneity in the joint-trajectories of cannabis use and FEP outcomes. Our findings support the need for intervention aimed at cannabis reduction among heavy users. Multi-disciplinary, trauma-informed interventions may benefit those with persistent cannabis use, given its associations with childhood and social adversity.
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 6
- The Impact of Cannabis Use on Cognitive Functioning in Patients With Schizophrenia: A Meta-analysis of Existing Findings and New Data in a First-Episode Sample Schizophrenia Bulletin July 25, 2010
- Risk-thresholds for the association between frequency of cannabis use and the development of psychosis: a systematic review and meta-analysis Psychological Medicine March 24, 2022
- Association between cannabis use and symptom dimensions in schizophrenia spectrum disorders: an individual participant data meta-analysis on 3053 individuals EClinicalMedicine September 8, 2023
- Cannabis use as a potential mediator between childhood adversity and first-episode psychosis: results from the EU-GEI case–control study Psychological Medicine May 4, 2023
- The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case-control study The Lancet Psychiatry May 1, 2019
and 1 more in the library