title: Substance use and sociodemographic background as risk factors for lifetime psychotic experiences in a non-clinical sample.
abstract: Psychotic experiences (PE) are relatively common in the general population. PE is associated with mental health impairment and may be predictive of clinical psychosis. Substance use predicts PE, but the association is insufficiently understood, particularly the role of illicit substances. The purpose of this study was to describe PE (visual and auditory hallucinations and delusions of reference and persecution) in a population characterized by high levels of substance use and to investigate substance use and sociodemographic background characteristics as risk factors for PE.
  
  
  
  We used data from the Norwegian Offender Mental Health and Addiction Study (NorMA), a cross-sectional survey of 1499 individuals from Norwegian prisons. The outcome was one, two, three or four types of PE during the lifetime. The association between different variables and PE was investigated using multinomial logistic regression with three outcome categories: 0 PE, 1-2 PE and 3-4 PE.
  
  
  
  The prevalence of lifetime PE was 53.7%. Several substances were strongly associated with PE: For cannabis, the adjusted relative risk ratio (RRR) of 1-2 PE was 2.78 (95% CI 1.89-4.10) and of 3-4 PE it was 4.36 (2.58-7.36). For amphetamine, the RRR of 1-2 PE was 3.26 (2.11-5.05) and of 3-4 PE it was 5.93 (3.72-9.46). For all variables, the association to PE was stronger with more types of PE.
  
  
  
  High levels of alcohol use, and lifetime use of cannabis, amphetamine and heroin were associated with PE. These effects were robust even when the substance use variables were adjusted against each other. This research received no specific grant from any funding agency, commercial or not-for-profit sectors.
authors.affiliation: Norwegian Centre for Addiction Research (SERAF), University of Oslo, Box 1039 Blindern, 0315 Oslo, Norway; Division of Mental Health and Addiction, Oslo University Hospital, Box 4950 Nydalen, 0424 Oslo, Norway; Norwegian National Advisory Unit on Concurrent Substance Abuse and Mental Health Disorders, Box 104, 2381 Brumunddal, Norway.
authors.forename: Eline Borger
authors.initials: EB
authors.lastname: Rognli
authors.affiliation: Norwegian Centre for Addiction Research (SERAF), University of Oslo, Box 1039 Blindern, 0315 Oslo, Norway.
authors.forename: Jørgen G
authors.initials: JG
authors.lastname: Bramness
authors.affiliation: Norwegian Centre for Addiction Research (SERAF), University of Oslo, Box 1039 Blindern, 0315 Oslo, Norway; Norwegian Institute of Public Health, Norway.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Skurtveit
authors.affiliation: Norwegian Centre for Addiction Research (SERAF), University of Oslo, Box 1039 Blindern, 0315 Oslo, Norway; The Correctional Service of Norway, Staff Academy, Oslo, Norway, Box 694, 4305 Sandnes, Norway. Electronic address: anne.bukten@medisin.uio.no.
authors.forename: Anne
authors.initials: A
authors.lastname: Bukten
mesh_terms: D000328:Adult; D015897:Comorbidity; D057237:Criminals / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D003702:Delusions / Q000453:epidemiology*; D005260:Female; D006212:Hallucinations / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D011618:Psychotic Disorders / Q000453:epidemiology*; D012307:Risk Factors; D012959:Socioeconomic Factors; D019966:Substance-Related Disorders / Q000453:epidemiology*; D055815:Young Adult
keywords: Drugs; Non-clinical population; Prison; Psychotic experiences; Psychotic symptoms; Substance use