title: Maltreatment in childhood substantially increases the risk of adult depression and anxiety in prospective cohort studies: systematic review, meta-analysis, and proportional attributable fractions.
abstract: BACKGROUND
  Literature supports a strong relationship between childhood maltreatment and mental illness but most studies reviewed are cross-sectional and/or use recall to assess maltreatment and are thus prone to temporality and recall bias. Research on the potential prospective impact of maltreatment reduction on the incidence of psychiatric disorders is scarce.
  
  
  METHODS
  Electronic databases and grey literature from 1990 to 2014 were searched for English-language cohort studies with criteria for depression and/or anxiety and non-recall measurement of childhood maltreatment. Systematic review with meta-analysis synthesized the results. Study quality, heterogeneity, and publication bias were examined. Initial screening of titles and abstracts resulted in 199 papers being reviewed. Eight high-quality articles met eligibility criteria. Population attributable fractions (PAFs) estimated potential preventive impact.
  
  
  RESULTS
  The pooled odds ratio (OR) between any type of maltreatment and depression was 2.03 [95% confidence interval (CI) 1.37-3.01] and 2.70 (95% CI 2.10-3.47) for anxiety. For specific types of maltreatment and depression or anxiety disorders, the ORs were: physical abuse (OR 2.00, 95% CI 1.25-3.19), sexual abuse (OR 2.66, 95% CI 1.88-3.75), and neglect (OR 1.74, 95% CI 1.35-2.23). PAFs suggest that over one-half of global depression and anxiety cases are potentially attributable to self-reported childhood maltreatment. A 10-25% reduction in maltreatment could potentially prevent 31.4-80.3 million depression and anxiety cases worldwide.
  
  
  CONCLUSIONS
  This review provides robust evidence of childhood maltreatment increasing the risk for depression and anxiety, and reinforces the need for effective programs and policies to reduce its occurrence.
authors.affiliation: School of Public Health,University of Saskatchewan,Saskatoon,Canada.
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.affiliation: School of Public Health,University of Saskatchewan,Saskatoon,Canada.
authors.forename: C
authors.initials: C
authors.lastname: D'Arcy
authors.affiliation: Department of Psychiatry,University of Saskatchewan,Saskatoon,Canada.
authors.forename: X
authors.initials: X
authors.lastname: Meng
mesh_terms: D054523:Adult Survivors of Child Abuse / Q000706:statistics & numerical data*; D001007:Anxiety / Q000453:epidemiology*; D001008:Anxiety Disorders / Q000453:epidemiology*; D003863:Depression / Q000453:epidemiology*; D003866:Depressive Disorder / Q000453:epidemiology*; D006801:Humans; D016017:Odds Ratio; D011446:Prospective Studies
keywords: Anxiety disorders; child abuse; childhood maltreatment; depression; population attributable fraction; projected effect