title: The natural history of self-harm from adolescence to young adulthood: a population-based cohort study.
abstract: BACKGROUND
  Knowledge about the natural history of self-harm is scarce, especially during the transition from adolescence to young adulthood, a period characterised by a sharp rise in self-inflicted deaths. From a repeated measures cohort of a representative sample, we describe the course of self-harm from middle adolescence to young adulthood.
  
  
  METHODS
  A stratified, random sample of 1943 adolescents was recruited from 44 schools across the state of Victoria, Australia, between August, 1992, and January, 2008. We obtained data pertaining to self-harm from questionnaires and telephone interviews at seven waves of follow-up, commencing at mean age 15·9 years (SD 0·49) and ending at mean age 29·0 years (SD 0·59). Summary adolescent measures (waves three to six) were obtained for cannabis use, cigarette smoking, high-risk alcohol use, depression and anxiety, antisocial behaviour and parental separation or divorce.
  
  
  RESULTS
  1802 participants responded in the adolescent phase, with 149 (8%) reporting self-harm, More girls (95/947 [10%]) than boys (54/855 [6%]) reported self-harm (risk ratio 1·6, 95% CI 1·2-2·2). We recorded a substantial reduction in the frequency of self-harm during late adolescence. 122 of 1652 (7%) participants who reported self-harm during adolescence reported no further self-harm in young adulthood, with a stronger continuity in girls (13/888) than boys (1/764). During adolescence, incident self-harm was independently associated with symptoms of depression and anxiety (HR 3·7, 95% CI 2·4-5·9), antisocial behaviour (1·9, 1·1-3·4), high-risk alcohol use (2·1, 1·2-3·7), cannabis use (2·4, 1·4-4·4), and cigarette smoking (1·8, 1·0-3·1). Adolescent symptoms of depression and anxiety were clearly associated with incident self-harm in young adulthood (5·9, 2·2-16).
  
  
  CONCLUSIONS
  Most self-harming behaviour in adolescents resolves spontaneously. The early detection and treatment of common mental disorders during adolescence might constitute an important and hitherto unrecognised component of suicide prevention in young adults.
  
  
  BACKGROUND
  National Health and Medical Research Council, Australia, and operational infrastructure support programme, Government of Victoria, Australia.
authors.affiliation: King's College London, Institute of Psychiatry, Health Service & Population Research Department, London, UK. paul.moran@kcl.ac.uk
authors.forename: Paul
authors.initials: P
authors.lastname: Moran
authors.forename: Carolyn
authors.initials: C
authors.lastname: Coffey
authors.forename: Helena
authors.initials: H
authors.lastname: Romaniuk
authors.forename: Craig
authors.initials: C
authors.lastname: Olsson
authors.forename: Rohan
authors.initials: R
authors.lastname: Borschmann
authors.forename: John B
authors.initials: JB
authors.lastname: Carlin
authors.forename: George C
authors.initials: GC
authors.lastname: Patton
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D012307:Risk Factors; D012309:Risk-Taking; D016728:Self-Injurious Behavior / Q000453:epidemiology* / Q000523:psychology; D011795:Surveys and Questionnaires; D014739:Victoria / Q000453:epidemiology; D055815:Young Adult