The impact of childhood psychological maltreatment on mental health outcomes in adulthood: a protocol for a systematic review and meta-analysis

BACKGROUND: Research suggests that childhood psychological maltreatment (i.e., emotional abuse and emotional neglect) is associated with mental health problems that persist into adulthood, for example anxiety, depression, post-traumatic stress disorder (PTSD), suicidal ideation, and aggression; however, a systematic review and meta-analysis of the existing literature would help clarify the magnitude and moderators of these associations, and the extent to which they may be affected by publication bias, as well as the methodological strengths and weakness of studies in this area. METHOD: The reporting of this protocol follows the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) Statement. Searches will be carried out via several databases, including Web of Science, Medline, PubMed, PsycINFO, Applied Social Science Index and Abstract, ERIC and EMBASE. Empirical peer-reviewed research articles that fit pre-specified eligibility criteria will be included in the review. Studies will be eligible if they include participants age 18 or over at time of mental health assessment, include information on childhood psychological maltreatment (emotional abuse and/or neglect) perpetrated by a primary caregiver or adult in the same household, and provide quantitative information on the association between these factors. Studies using prospective and retrospective designs and written in either English or Chinese will be eligible. Two independent reviewers will screen and assess studies for inclusion in the review as well as extract the data, with consensus reached through discussion in cases of discrepancy. A third reviewer will be consulted to resolve any discrepancies that remain. The relevant Newcastle–Ottawa scales will be used for assessing the quality of studies. If a sufficient number of comparable studies are retrieved, a meta-analysis will be conducted using a random effects model. Study-level moderators (i.e., year of publication, quality of the study and study geographical location) will be examined in the meta-analyses. DISCUSSION: This systematic review will provide an understanding of the long-term effects of childhood psychological maltreatment on adult mental health, which adds to previous reviews focusing primarily on the effects of physical and sexual abuse. The results of the review will help inform clinical practice in approaches to treating those with a history of psychological maltreatment in childhood. The gaps and weaknesses in the evidence identified will also inform recommendations for future research.