title: Dose-response effect between cannabis use and psychosis liability in a non-clinical population: evidence from a snowball sample.
abstract: This study aimed to explore the associations between daily cannabis use and the specific profiles of subclinical symptoms in a non-clinical population obtained through snowball sampling, taking into account alcohol use, other drug use, social exclusion and age at onset of cannabis use. We included 85 daily cannabis users and 100 non-daily cannabis users. Both the case and the control populations were identified by snowball sampling. Daily cannabis use was associated with more alcohol intake and other drug use, as well as with early onset in the use of cannabis. Daily cannabis use appeared to exert a dose-response effect on first-rank symptoms, mania symptoms and auditory hallucinations, even after adjusting for sex, age, other drug use, social exclusion and age at onset of cannabis use. The paranoid dimension was only associated with the heaviest consumption of cannabis. Initial age of cannabis use modified the effects of daily cannabis use on the first-rank and voices experiences. Daily cannabis use was associated with significantly more first-rank and voices experiences among those subjects who started to use cannabis before 17 years of age. Our study supports the association of psychotic experiences with cannabis use even among non-psychotic subjects.
authors.affiliation: Grupo Psicosis y Neurodesarrollo, Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocio/CSIC/Universidad de Sevilla, Unidad de Hospitalización de Salud Mental, Sevilla, Spain. Miguel.ruiz.veguilla.sspa@juntadeandalucia.es
authors.forename: Miguel
authors.initials: M
authors.lastname: Ruiz-Veguilla
authors.forename: María Luisa
authors.initials: ML
authors.lastname: Barrigón
authors.forename: Laureano
authors.initials: L
authors.lastname: Hernández
authors.forename: José Luis
authors.initials: JL
authors.lastname: Rubio
authors.forename: Manuel
authors.initials: M
authors.lastname: Gurpegui
authors.forename: Fernando
authors.initials: F
authors.lastname: Sarramea
authors.forename: Jorge
authors.initials: J
authors.lastname: Cervilla
authors.forename: Blanca
authors.initials: B
authors.lastname: Gutiérrez
authors.forename: Anthony
authors.initials: A
authors.lastname: James
authors.forename: Maite
authors.initials: M
authors.lastname: Ferrin
mesh_terms: D000328:Adult; D017668:Age of Onset; D000428:Alcohol Drinking / Q000453:epidemiology / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000453:epidemiology* / Q000523:psychology*; D016017:Odds Ratio; D011594:Psychometrics; D011618:Psychotic Disorders / Q000453:epidemiology*; D013030:Spain / Q000453:epidemiology; D055815:Young Adult