Background: Robust evidence has demonstrated that cannabis use increasesthe risk to develop psychotic disorders. However, a limited number of studieshave investigated if and how cannabis use influences psychopathologyprofiles at first episode psychosis (FEP).Based on the evidence that dopamine dysfunction contributes to explainpositive symptoms in psychosis, and that the main cannabis’ psychoactivecomponent, Δ9-Tetrahydrocannabinol (THC), modulates the dopaminesystem, we hypothesise that: 1) positive symptoms at FEP are more commonamong psychotic patients who used cannabis compared with neverusers; 2) this association is a dose-response relationship.Methods: We analyzed a sample of 1130 FEP patients as part of the EUGEIstudy, recruited across six countries. The MRC Socio-demographic Schedulewas used to collect sociodemographic information. Psychopathology wasassessed with the OPerational CRITeria (OPCRIT), and symptom itemswere analyzed using Mplus to estimate a multidimensional model of psychosis.The Cannabis Experience Questionnaire modified version (CEQmv)was administered to collect information on cannabis, and different patternsof use were computed based on frequency of consumption and type of cannabis,as a proxy of exposure to THC.Results: The lifetime rate of cannabis use was 63%. Fifty-five percent ofcannabis users consumed mostly high-potency cannabis, and 46% showeda daily frequency. Mixed-effects linear regression revealed that frequencyof cannabis use was associated with the positive symptom dimensionscore. Daily users of high-potency cannabis presented with the strongest association (Β=0.19, 95%CI=0.02–0.38), even after gender, age, ethnicity,other drug use, and study site were controlled for.Discussion: Our results show that patients with a history of daily use ofhigh potency cannabis express more positive symptoms at psychosis onset,even after taking into account other substance use and relevant sociodemographicfactors.
|Numero di pagine||2|
|Stato di pubblicazione||Published - 2018|