title: Is socioeconomic status in early life associated with drug use? A systematic review of the evidence.
abstract: OBJECTIVE
  To conduct a systematic review of longitudinal studies that examined the association between childhood socioeconomic status (SES) and illegal drug use in later life.
  
  
  METHODS
  Systematic search with an agreed list of search items was used to identify all longitudinal population-based studies that examined the association between childhood SES and later drug use. These included MEDLINE (1966-2005), EMBASE (1990-2005), CINAHL (1982-2005) and PsychInfo (1806-2005), and specialist databases of the Lindesmith Library, Drugscope and Addiction Abstracts. Foreign-language papers were included. Abstracts were screened independently by two reviewers. If there was disagreement to accept or reject the abstract, then a third reviewer acted as arbiter. Data were extracted by one of the authors.
  
  
  RESULTS
  Eleven relevant papers were identified (two birth cohorts and nine papers on school-aged cohorts). There was consistent evidence to support an association between lower childhood SES and later drug use, primarily cannabis use. However, few studies examined cannabis dependence, and studies of more problematic forms of drug use gave contradictory results.
  
  
  CONCLUSIONS
  We found consistent, though weak, evidence to support the assumption that childhood disadvantage is associated with later cannabis use. Further research is needed to clarify this issue and to inform future policies and public health messages.
authors.affiliation: Academic Unit of Psychiatry, University of Bristol, Bristol, UK.
authors.forename: James Z
authors.initials: JZ
authors.lastname: Daniel
authors.forename: Matthew
authors.initials: M
authors.lastname: Hickman
authors.forename: John
authors.initials: J
authors.lastname: Macleod
authors.forename: Nicola
authors.initials: N
authors.lastname: Wiles
authors.forename: Anne
authors.initials: A
authors.lastname: Lingford-Hughes
authors.forename: Michael
authors.initials: M
authors.lastname: Farrell
authors.forename: Ricardo
authors.initials: R
authors.lastname: Araya
authors.forename: Petros
authors.initials: P
authors.lastname: Skapinakis
authors.forename: Jon
authors.initials: J
authors.lastname: Haynes
authors.forename: Glyn
authors.initials: G
authors.lastname: Lewis