Intimate Partner Violence and Incident Depressive Symptoms and Suicide Attempts: A Systematic Review of Longitudinal Studies

: Karen Devries and colleagues conduct a systematic review of longitudinal studies to evaluate the direction of association between symptoms of depression and intimate partner violence. Background: Depression and suicide are responsible for a substantial burden of disease globally. Evidence suggests that intimate partner violence (IPV) experience is associated with increased risk of depression, but also that people with mental disorders are at increased risk of violence. We aimed to investigate the extent to which IPV experience is associated with incident depression and suicide attempts, and vice versa, in both women and men. Methods and Findings: We conducted a systematic review and meta-analysis of longitudinal studies published before February 1, 2013. More than 22,000 records from 20 databases were searched for studies examining physical and/or sexual intimate partner or dating violence and symptoms of depression, diagnosed major depressive disorder, dysthymia, mild depression, or suicide attempts. Random effects meta-analyses were used to generate pooled odds ratios (ORs). Sixteen studies with 36,163 participants met our inclusion criteria. All studies included female participants; four studies also included male participants. Few controlled for key potential confounders other than demographics. All but one depression study measured only depressive symptoms. For women, there was clear evidence of an association between IPV and incident depressive symptoms, with 12 of 13 studies showing a positive direction of association and 11 reaching statistical significance; pooled OR from six studies = 1.97 (95% CI 1.56–2.48, I2 = 50.4%, pheterogeneity = 0.073). There was also evidence of an association in the reverse direction between depressive symptoms and incident IPV (pooled OR from four studies = 1.93, 95% CI 1.51–2.48, I2 = 0%, p = 0.481). IPV was also associated with incident suicide attempts. For men, evidence suggested that IPV was associated with incident depressive symptoms, but there was no clear evidence of an association between IPV and suicide attempts or depression and incident IPV. Conclusions: In women, IPV was associated with incident depressive symptoms, and depressive symptoms with incident IPV. IPV was associated with incident suicide attempts. In men, few studies were conducted, but evidence suggested IPV was associated with incident depressive symptoms. There was no clear evidence of association with suicide attempts. Background: Depression and suicide are responsible for a substantial proportion of the global disease burden. Depression—an overwhelming feeling of sadness and hopelessness that can last for months or years—affects more than 350 million people worldwide. It is the eleventh leading cause of global disability-adjusted life-years (a measure of overall disease burden), and it affects one in six people at some time during their lives. Globally, about a million people commit suicide every year, usually because they have depression or some other mental illness. Notably, in cross-sectional studies (investigations that look at a population at a single time point), experience of intimate partner violence (IPV, also called domestic violence) is strongly and consistently associated with both depressive disorders and suicide. IPV, like depression and suicide, is extremely common—in multi-country studies, 15%–71% of women report being physically assaulted at some time during their lifetime. IPV is defined as physical, sexual, or psychological harm by a current or former partner or spouse; men as well as women can be the victims of IPV. Why Was This Study Done?: It may seem obvious to assume that IPV is causally related to subsequent depression and suicidal behavior. However, cross-sectional studies provide no information about causality, and it is possible that depression and/or suicide attempts cause subsequent IPV or that there are common risk factors for IPV, depression, and suicide. For example, individuals with depressive symptoms may be more accepting of partners with characteristics that predispose them to use violence, or early life exposure to violence may predispose individuals to both depression and choosing violent partners. Here, as part of the Global Burden of Disease Study 2010, the researchers investigate the extent to which experience of IPV is associated with subsequent depression and suicide attempts and vice versa in both men and women by undertaking a systematic review and meta-analysis of longitudinal studies that have examined IPV, depression, and suicide attempts. A systematic review uses predefined criteria to identify all the research on a given topic, meta-analysis combines the results of several studies, and longitudinal studies track people over time to investigate associations between specific characteristics and outcomes. What Did the Researchers Do and Find?: The researchers identified 16 longitudinal studies involving a total of 36,163 participants that met their inclusion criteria. All the studies included women, but only four also included men. All the studies were undertaken in high- and middle-income countries. For women, 11 studies showed a statistically significant association (an association unlikely to have occurred by chance) between IPV and subsequent depressive symptoms. In a meta-analysis of six studies, experience of IPV nearly doubled the risk of women subsequently reporting depressive symptoms. In addition, there was evidence of an association in the reverse direction. In a meta-analysis of four studies, depressive symptoms nearly doubled the risk of women subsequently experiencing IPV. IPV was also associated with subsequent suicide attempts among women. For men, there was some evidence from two studies that IPV was associated with depressive symptoms but no evidence for an association between IPV and subsequent suicide attempt or between depressive symptoms and subsequent IPV. What Do These Findings Mean?: These findings suggest that women who are exposed to IPV are at increased risk of subsequent depression and that women who are depressed are more likely to be at risk of IPV. They also provide evidence of an association between IPV and subsequent suicide attempt for women. The study provides little evidence for similar relationships among men, but additional studies are needed to confirm this finding. Moreover, the accuracy of these findings is likely to be affected by several limitations of the study. For example, few of the included studies controlled for other factors that might have affected both exposure to IPV and depressive symptoms, and none of the studies considered the effect of emotional violence on depressive symptoms and suicide attempts. Nevertheless, these findings have two important implications. First, they suggest that preventing violence against women has the potential to reduce the global burden of disease related to depression and suicide. Second, they suggest that clinicians should pay attention to past experiences of violence and the risk of future violence when treating women who present with symptoms of depression. Additional Information: Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001439.