Impact of Cannabis Use on the Development of Psychotic Disorders

Abstract

The link between cannabis use and psychosis comprises three distinct relationships: acute psychosis associated with cannabis intoxication, acute psychosis that lasts beyond the period of acute intoxication, and persistent psychosis not time-locked to exposure. Experimental studies reveal that cannabis, tetrahydrocannabinol (THC) and synthetic cannabinoids reliably produce transient positive, negative, and cognitive symptoms in healthy volunteers. Case-studies indicate that cannabinoids can induce acute psychosis which lasts beyond the period of acute intoxication but resolves within a month. Exposure to cannabis in adolescence is associated with a risk for later psychotic disorder in adulthood; this association is consistent, temporally related, shows a dose-response, and is biologically plausible. However, cannabis is neither necessary nor sufficient to cause a persistent psychotic disorder. More likely it is a component cause that interacts with other factors to result in psychosis. The link between cannabis and psychosis is moderated by age at onset of cannabis use, childhood abuse and genetic vulnerability. While more research is needed to better characterize the relationship between cannabinoid use and the onset and persistence of psychosis, clinicians should be mindful of the potential risk of psychosis especially in vulnerable populations, including adolescents and those with a psychosis diathesis.

Adolescent THC exposure in female rats leads to cognitive deficits through a mechanism involving chromatin modifications in the prefrontal cortex

“…Despite epidemiological studies suggesting that heavy can nabis use during adolescence increases the risk for neuro psychiatric disorders later in life, [1][2][3] cannabis remains the world's most widely used illicit substance, 4 especially among adolescents. It is therefore necessary to comprehend thor oughly the molecular underpinnings enhancing adolescent brain vulnerability to adverse effects from cannabis.…”

mGluR2/3 agonist LY379268 rescues NMDA and GABAA receptor level deficits induced in a two-hit mouse model of schizophrenia

“…Additionally, stressors that contribute to the development of schizophrenia symptoms include the consumption of illicit substances such as cannabis (Wilkinson et al, 2014), methamphetamine (Callaghan et al, 2012) and phencyclidine (PCP) during adolescence (Swartz et al, 2014). Preclinical animal models that combine genetic risk factors with late developmental stressors result in a wide range of behavioral and neurochemical impairments, strongly supporting the "two-hit" hypothesis of schizophrenia (Karl and Arnold, 2014).…”

Le cannabis et ses effets délétères : pour un débat plus nuancé

“…Ainsi, le cannabis pourrait agir à titre de déclencheur de maladie psychotique chez des individus présentant une vulné-rabilité particulière à cet effet. Le rôle du cannabis dans le déclenchement de la psychose pourrait être encore plus complexe ; cette substance pouvant également agir de façon additive, voire peut-être synergique, avec d'autres stresseurs environnementaux pour déclencher la psychose (van Winkel et Kuepper, 2014 ;Wilkinson, Radhakrishnan et D'Souza, 2014). Deux études américaines ont par exemple observé un excès de cas de psychoses chez les adolescents consommateurs de cannabis Tous droits réservés © Drogues, santé et société, vol.…”