People who have been subject to abuse are more likely to experience physical and mental health effects than previously thought, according to a new study.

In a global review and meta-analysis of evidence published in Nature Medicine today, researchers have found that there are elevated risks between intimate partner violence or childhood sexual abuse and some health conditions, including major depressive disorder, maternal miscarriage for partners, and alcohol misuse and self-harm among children.

Globally, one in three ever-partnered women have experienced intimate partner violence in their lifetime, and around 20% of young women and 10% of young men have experienced some form of childhood sexual abuse. However, research investigating health outcomes associated with intimate partner violence and childhood sexual abuse has been limited.

The authors found that exposure to intimate partner violence had a moderate association with an increased risk of major depressive disorders (63%) and an increased risk of maternal abortion and miscarriage (35%). Childhood sexual abuse was shown to be moderately associated with an increased risk of alcohol use and an increased risk of self-harm (45% and 35%, respectively). The authors indicate these findings are larger in magnitude and more extensive than previously suggested.

Dr. Joht Singh Chandan, Clinical Associate Professor in Public Health at the University of Birmingham and senior co-lead author of the paper, said, "This comprehensive study marks a significant step in understanding the profound health impacts of intimate partner violence against women and childhood sexual abuse. Our findings reveal not only the alarming associations these forms of violence have with conditions like major depressive disorder, miscarriage, alcohol use disorders, and self-harm, but also underscore the urgent need for robust preventive measures and support systems."

Professor Emmanuela Gakidou from the Institute of Health Metrics and Evaluation at the University of Washington and senior co-lead author of the paper, said, "While we've shed light on these critical health issues, our research also highlights the gaps in current knowledge and the necessity for continued investigation to fully grasp the extensive consequences of such violence. It's imperative that we use these insights to inform policy, health care, and community interventions, ensuring a safer and healthier future for individuals affected by these pervasive forms of violence."

Dr. Nicholas Metheny, Assistant Professor in the School of Nursing and Health Studies at the University of Miami, said, "Our research marks a pivotal shift in how we perceive the societal and health burdens of intimate partner violence (IPV). Previously, our evidence primarily highlighted IPV's contribution to HIV and depression, substantially underestimating its broader impact. This study expands our understanding, revealing IPV's extensive influence on a wider range of poor health outcomes.

"This new perspective is crucial in elevating IPV as a public health imperative in the global sphere, hopefully igniting both political and scientific momentum towards effective prevention and intervention strategies."

4,000 studies reviewed—229 suitable for inclusion

Searching through papers published from seven databases, Emmanuella Gakidou, and colleagues identified the available literature on intimate partner violence and childhood sexual abuse and their associated health effects. They reviewed over 4,000 studies, of which 229 studies met the criteria for inclusion.

Using the burden of proof methodology (a meta-analytic approach for estimating a conservative measure of the elevated or reduced risk of a particular health outcome after exposure to a harmful or protective risk factor), they evaluated the strength of evidence connecting intimate partner violence and/or childhood sexual abuse to health outcomes, which were supported by at least three studies.

Additional potential health outcomes were also initially identified in the study, including an association of maternal hypertensive disorders with intimate partner violence and an association of smoking with childhood sexual abuse. However, the research concludes that due to a scarcity of evidence, these could not be included in the meta-analysis.

The authors note that the studies are observational and cannot demonstrate causality and highlight that their findings are limited owing to the limited number of studies that explore these relationships. They suggest that their research demonstrates the wide-ranging health effects of intimate partner violence and childhood sexual abuse but emphasize the need for further research to strengthen the evidence base.