The Long-Term Health Consequences of Child Physical Abuse, Emotional Abuse, and Neglect: A Systematic Review and Meta-Analysis

Abstract

Child sexual abuse is considered a modifiable risk factor for mental disorders across the life course. However the long-term consequences of other forms of child maltreatment have not yet been systematically examined. The aim of this study was to summarise the evidence relating to the possible relationship between child physical abuse, emotional abuse, and neglect, and subsequent mental and physical health outcomes. A systematic review was conducted using the Medline, EMBASE, and PsycINFO electronic databases up to 26 June 2012. Published cohort, cross-sectional, and case-control studies that examined non-sexual child maltreatment as a risk factor for loss of health were included. All meta-analyses were based on quality-effects models. Out of 285 articles assessed for eligibility, 124 studies satisfied the pre-determined inclusion criteria for meta-analysis. Statistically significant associations were observed between physical abuse, emotional abuse, and neglect and depressive disorders (physical abuse [odds ratio (OR) = 1.54; 95% CI 1.16–2.04], emotional abuse [OR = 3.06; 95% CI 2.43–3.85], and neglect [OR = 2.11; 95% CI 1.61–2.77]); drug use (physical abuse [OR = 1.92; 95% CI 1.67–2.20], emotional abuse [OR = 1.41; 95% CI 1.11–1.79], and neglect [OR = 1.36; 95% CI 1.21–1.54]); suicide attempts (physical abuse [OR = 3.40; 95% CI 2.17–5.32], emotional abuse [OR = 3.37; 95% CI 2.44–4.67], and neglect [OR = 1.95; 95% CI 1.13–3.37]); and sexually transmitted infections and risky sexual behaviour (physical abuse [OR = 1.78; 95% CI 1.50–2.10], emotional abuse [OR = 1.75; 95% CI 1.49–2.04], and neglect [OR = 1.57; 95% CI 1.39–1.78]). Evidence for causality was assessed using Bradford Hill criteria. While suggestive evidence exists for a relationship between maltreatment and chronic diseases and lifestyle risk factors, more research is required to confirm these relationships. This overview of the evidence suggests a causal relationship between non-sexual child maltreatment and a range of mental disorders, drug use, suicide attempts, sexually transmitted infections, and risky sexual behaviour. All forms of child maltreatment should be considered important risks to health with a sizeable impact on major contributors to the burden of disease in all parts of the world. The awareness of the serious long-term consequences of child maltreatment should encourage better identification of those at risk and the development of effective interventions to protect children from violence. Please see later in the article for the Editors' Summary Child maltreatment—the abuse and neglect of children—is a global problem. There are four types of child maltreatment—sexual abuse (the involvement of a child in sexual activity that he or she does not understand, is unable to give consent to, or is not developmentally prepared for), physical abuse (the use of physical force that harms the child's health, survival, development, or dignity), emotional abuse (the failure to provide a supportive environment by, for example, verbally threatening the child), and neglect (the failure to provide for all aspects of the child's well-being). Most child maltreatment is perpetrated by parents or parental guardians, many of whom were maltreated themselves as children. Other risk factors for parents abusing their children include poverty, mental health problems, and alcohol and drug misuse. Although there is considerable uncertainty about the frequency and severity of child maltreatment, according to the World Health Organization (WHO) about 20% of women and 5%–10% of men report being sexually abused as children, and the prevalence of physical abuse in childhood may be 25%–50%. Child maltreatment has a large public health impact. Sometimes this impact is immediate and direct (injuries and deaths), but, more often, it is long-term, affecting emotional development and overall health. For child sexual abuse, the relationship between abuse and mental disorders in adult life is well-established. Exposure to other forms of child maltreatment has also been associated with a wide range of psychological and behavioral problems, but the health consequences of physical abuse, emotional abuse, and neglect have not been systematically examined. A better understanding of the long-term health effects of child maltreatment is needed to inform maltreatment prevention strategies and to improve treatment for children who have been abused or neglected. In this systematic review and meta-analysis, the researchers quantify the association between exposure to physical abuse, emotional abuse, and neglect in childhood and mental health and physical health outcomes in later life. A systematic review uses predefined criteria to identify all the research on a given topic; a meta-analysis is a statistical approach that combines the results of several studies. The researchers identified 124 studies that investigated the relationship between child physical abuse, emotional abuse, or neglect and various health outcomes. Their meta-analysis of data from these studies provides suggestive evidence that child physical abuse, emotional abuse, and neglect are causally linked to mental and physical health outcomes. For example, emotionally abused individuals had a three-fold higher risk of developing a depressive disorder than non-abused individuals (an odds ratio [OR] of 3.06). Physically abused and neglected individuals also had a higher risk of developing a depressive disorder than non-abused individuals (ORs of 1.54 and 2.11, respectively). Other mental health disorders associated with child physical abuse, emotional abuse, or neglect included anxiety disorders, drug abuse, and suicidal behavior. Individuals who had been non-sexually maltreated as children also had a higher risk of sexually transmitted diseases and/or risky sexual behavior than non-maltreated individuals. Finally, there was weak and inconsistent evidence that child maltreatment increased the risk of chronic diseases and lifestyle risk factors such as smoking. By providing suggestive evidence of a causal link between non-sexual child maltreatment and mental health disorders, drug use, suicide attempts, and sexually transmitted diseases and risky sexual behavior, these findings contribute to our understanding of the non-injury health impacts of child maltreatment. Although most of the studies included in the meta-analysis were undertaken in high-income countries, the findings suggest that this link occurs in both high- and low-to-middle-income countries. They also suggest that neglect may be as harmful as physical and emotional abuse. However, they need to be interpreted carefully because of the limitations of this meta-analysis, which include the possibility that children who have been abused may share other, unrecognized factors that are actually the cause of their later mental health problems. Importantly, this confirmation that physical abuse, emotional abuse, and neglect in childhood are important risk factors for a range of health problems draws attention to the need to develop evidence-based strategies for preventing child maltreatment both to reduce childhood suffering and to alleviate an important risk factor for later health problems. Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001349.