Daily use of high-potency cannabis is associated with more positive symptoms in first-episode psychosis patients: the EU-GEI case–control study

Abstract

Background Daily use of high-potency cannabis has been reported to carry a high risk for developing a psychotic disorder. However, the evidence is mixed on whether any pattern of cannabis use is associated with a particular symptomatology in first-episode psychosis (FEP) patients. Method We analysed data from 901 FEP patients and 1235 controls recruited across six countries, as part of the European Network of National Schizophrenia Networks Studying Gene-Environment Interactions (EU-GEI) study. We used item response modelling to estimate two bifactor models, which included general and specific dimensions of psychotic symptoms in patients and psychotic experiences in controls. The associations between these dimensions and cannabis use were evaluated using linear mixed-effects models analyses. Results In patients, there was a linear relationship between the positive symptom dimension and the extent of lifetime exposure to cannabis, with daily users of high-potency cannabis having the highest score (B = 0.35; 95% CI 0.14–0.56). Moreover, negative symptoms were more common among patients who never used cannabis compared with those with any pattern of use (B = −0.22; 95% CI −0.37 to −0.07). In controls, psychotic experiences were associated with current use of cannabis but not with the extent of lifetime use. Neither patients nor controls presented differences in depressive dimension related to cannabis use. Conclusions Our findings provide the first large-scale evidence that FEP patients with a history of daily use of high-potency cannabis present with more positive and less negative symptoms, compared with those who never used cannabis or used low-potency types.

The continuity of effect of schizophrenia polygenic risk score and patterns of cannabis use on transdiagnostic symptom dimensions at first-episode psychosis: findings from the EU-GEI study

“…Psychoactive compounds in recreational cannabis may elicit positive symptoms by interacting with the endocannabinoid system [ 16 ]; moreover, converging evidence suggests that cannabis users who develop psychosis have less neurodevelopmental impairments than their non-user counterparts [ 17 ]. Supporting this, in a dimensional representation of psychosis, we see that cannabis users presented at FEP with more positive and fewer negative symptoms [ 15 ], the latter considered a proxy of early neurodevelopmental impairment in psychosis [ 18 ].…”

“…Within this methodological framework, we have recently investigated the relationship between a bi-factor model of psychopathology at first-episode psychosis (FEP) [ 14 ] and cannabis consumption [ 15 ]. Psychoactive compounds in recreational cannabis may elicit positive symptoms by interacting with the endocannabinoid system [ 16 ]; moreover, converging evidence suggests that cannabis users who develop psychosis have less neurodevelopmental impairments than their non-user counterparts [ 17 ].…”

“…In the present study, we sought to examine the continuity of the effect of heavy cannabis use and genetic liability to psychotic disorders across the continuum of psychosis symptoms, including general and specific dimensions from a multinational sample of FEP [ 14 ] and controls representative of the population at risk [ 15 ].…”

Is the Adolescent Brain at Greater Vulnerability to the Effects of Cannabis? A Narrative Review of the Evidence

“…Patterns of cannabis use have been shown to be associated with greater harm in general when used regularly as opposed to infrequently; daily as opposed to once in a while; and when used in greater amount as opposed to smaller amounts (4,(43)(44)(45)(46). Recent changes in cannabinoid consumption may have further increased the potential of harm in adolescent users.…”

Modelo computacional para apoio à decisão clínica no diagnóstico de transtornos psicóticos

“…O grupo de dados CEQ descreve sobre a experiência do indivíduo em relação ao uso da maconha. Corroborando com a literatura atual, em estudos clínicos e epidemiológicos feitos também com dados da colaboração EU-GEI, existem evidências de que a frequência e quantidade do uso de maconha podem contribuir na variação de incidência de transtornos psicóticos (EU-GEI WP2 GROUP COLLABORATORS, 2019;QUATTRONE et al, 2020).…”