title: Age at initiation of amphetamine use and age at onset of psychosis: the Australian Survey of High Impact Psychosis.
abstract: Individuals with a psychotic disorder who had a premorbid history of amphetamine use (n=382) were analyzed in groups according to age of initiation to amphetamine (AIA) and mean number of years of duration of premorbid exposure to amphetamine (DPEA) was calculated. Univariate General Linear Models were used to test for group differences in age at onset of psychotic illness (AOI) and DPEA. Although a temporal direct relationship between AIA and AOI was detected (mean duration 5.3 years), our findings suggested this association was spurious and better explained by a later initiation to amphetamine than to cannabis (by 2-3 years).
authors.affiliation: School of Psychiatry and Clinical Neurosciences, and Centre for Clinical Research in Neuropsychiatry, University of Western Australia, Australia; Clinical Research Centre, North Metropolitan Health Service - Mental Health, WA, Australia; Peel and Rockingham Kwinana Mental Health Service, South Metropolitan Area Health Service, Perth, Australia. Electronic address: brian.power@health.wa.gov.au.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Power
authors.affiliation: School of Psychiatry and Clinical Neurosciences, and Centre for Clinical Research in Neuropsychiatry, University of Western Australia, Australia; Clinical Research Centre, North Metropolitan Health Service - Mental Health, WA, Australia. Electronic address: nikos.stefanis@uwa.edu.au.
authors.forename: Nikos C
authors.initials: NC
authors.lastname: Stefanis
authors.affiliation: School of Psychiatry and Clinical Neurosciences, and Centre for Clinical Research in Neuropsychiatry, University of Western Australia, Australia; Clinical Research Centre, North Metropolitan Health Service - Mental Health, WA, Australia. Electronic address: milan.dragovic@health.wa.gov.au.
authors.forename: Milan
authors.initials: M
authors.lastname: Dragovic
authors.affiliation: School of Psychiatry and Clinical Neurosciences, and Centre for Clinical Research in Neuropsychiatry, University of Western Australia, Australia. Electronic address: assen.jablensky@health.wa.gov.au.
authors.forename: Assen
authors.initials: A
authors.lastname: Jablensky
authors.affiliation: St. Vincent's Hospital, University of Melbourne, Melbourne Australia. Electronic address: David.Castle@svhm.org.au.
authors.forename: David
authors.initials: D
authors.lastname: Castle
authors.affiliation: School of Psychiatry and Clinical Neurosciences, and Centre for Clinical Research in Neuropsychiatry, University of Western Australia, Australia. Electronic address: vera.morgan@health.wa.gov.au.
authors.forename: Vera
authors.initials: V
authors.lastname: Morgan
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D019969:Amphetamine-Related Disorders / Q000453:epidemiology*; D001315:Australia / Q000453:epidemiology; D002391:Catchment Area, Health / Q000706:statistics & numerical data; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000175:diagnosis / Q000453:epidemiology*; D055815:Young Adult
keywords: AIA; AOI; Amphetamine; Cannabis; Causality; DIP; DPEA; Diagnostic Interview for Psychosis; Psychosis; SHIP; Schizophrenia; Survey of High Impact Psychosis; age at initiation to amphetamine; age at onset of illness; duration of premorbid exposure to amphetamine