As a leading cause of disease burden worldwide, depressive disorders are a global health priority. This burden is disproportionately shouldered by women, with most epidemiological studies reporting approximately twice as many women experiencing major depressive disorders as men; however, this disparity may be even higher in certain countries.11. Salk RH, Hyde JS, Abramson LY. Gender differences in depression in representative national samples: meta-analyses of diagnoses and symptoms. Psychol Bull. 2017;143:783-822.,22. Yu S. Uncovering the hidden impacts of inequality on mental health: a global study. Transl Psychiatry. 2018;8:98. Violence exposure across the lifespan is also a pervasive problem that is unevenly distributed across the sexes, depending on the type of violence. Despite high prevalence rates of depression and violence, consistent links between the two, and evidence of sex differentials, pathways and mechanisms remain poorly understood. Using a novel approach, Carpena et al. attempted to tease apart these nuances in a nationally representative sample in Brazil, adopting a counterfactual framework and multiple modeling approach that examined the additive and multiplicative interactions between biological sex and violence, as well as violence as a mediator between biological sex and outcome.33. Carpena MX, Costa FS, Martins-Silva T, Xavier MO, Loret de Mola C. Why Brazilian women suffer more from depression and suicidal ideation: a mediation analysis of the role of violence. Braz J Psychiatry. 2020 Jun 1;S1516-44462020005015201. doi: 10.1590/1516-4446-2019-0572. Online ahead of print.
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Contradicting the commonly held dogma that sex differences can only be investigated through moderation or stratification, the authors found no evidence of multiplicative interaction, although violence exposure in the last 12 months was a significant mediator, accounting for 10.6% of the association between sex and major depression and 8.0% of the association between sex and suicidal ideation.
The fact that exposure to violence was found to be a mediator raises the question of how pathways in the model are related. How is biological sex, as explicitly defined in the current study, directly associated with violence? Aside from the obvious size and strength difference between male and female mammals, there is extensive research supporting underlying mechanisms of sex differences related to aggression that involve sexually dimorphic neurobiological systems underpinning variations in stress, risk-taking, impulsivity, empathy, and punishment sensitivity.44. Niehoff D. Not hardwired: the complex neurobiology of sex differences in violence. Violence Gend. 2014;1:19-24. More specifically, there is robust evidence for sex differences in neural structure and function and the chemistry of the human brain, especially differences related to the prefrontal cortex and limbic system. These areas are associated with emotional information processing, impulse control and moral cognition,44. Niehoff D. Not hardwired: the complex neurobiology of sex differences in violence. Violence Gend. 2014;1:19-24. as well as larger relative total gray matter volume in women, which correlates with higher cooperativeness and altruistic behavior.55. Sacher J, Neumann J, Okon-Singer H, Gotowiec S, Villringer A. Sexual dimorphism in the human brain: evidence from neuroimaging. Magn Reson Imaging. 2013;31:366-75. While much of the literature on sexually dimorphic neurobiology provides clues related to sex differences in the propensity to aggressive or violent behavior, it does not necessarily account for why females would be at greater risk of violence victimization. Risk of violence exposure is not adequately captured by the traditional dichotomy of biological sex. Violence occurs within complex social, local/cultural, gendered systems which may exacerbate or mitigate the risk of violence perpetration and victimization.
Although sex and gender are not mutually exclusive constructs, they are frequently (and erroneously) used interchangeably in the literature. There is increasing recognition by funding agencies and journals to differentiate between biological sex and gender identity. Much of the research to date does not adequately capture both.66. Johnson JL, Greaves L, Repta R. Better science with sex and gender: facilitating the use of a sex and gender-based analysis in health research. Int J Equity Health. 2009;8:14. Some of the challenges may be related to methodological issues, given that there is limited consensus on the measurement of gender, and despite acknowledgement that it occurs along a continuum, researchers consistently dichotomize variables that may limit the validity of our understanding, given the multi-dimensional nature of sex and gender.66. Johnson JL, Greaves L, Repta R. Better science with sex and gender: facilitating the use of a sex and gender-based analysis in health research. Int J Equity Health. 2009;8:14. In their study, Carpena et al.33. Carpena MX, Costa FS, Martins-Silva T, Xavier MO, Loret de Mola C. Why Brazilian women suffer more from depression and suicidal ideation: a mediation analysis of the role of violence. Braz J Psychiatry. 2020 Jun 1;S1516-44462020005015201. doi: 10.1590/1516-4446-2019-0572. Online ahead of print.
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explicitly highlight biological sex as their main predictor, which is a common limitation in many epidemiological surveys. While these results raise important questions about the potential contribution of biological sex differences to mental health outcomes in the context of violence, they do not address the likely contribution of gender and other socially related factors. Gender systems sustain the risk of violence against women through biased norms, practices, and relations across multiple levels, including families, the workplace, and intimate relationships.77. McCarthy KJ, Mehta R, Haberland NA. Gender, power, and violence: a systematic review of measures and their association with male perpetration of IPV. PLoS One. 2018;13:e0207091. These same social factors reinforce systemic gender inequalities with negative consequences for health,88. Heise L, Greene ME, Opper N, Stavropoulou M, Harper C, Nascimento M, et al. Gender inequality and restrictive gender norms: framing the challenges to health. Lancet. 2019;393:2440-54. including depressive disorders.22. Yu S. Uncovering the hidden impacts of inequality on mental health: a global study. Transl Psychiatry. 2018;8:98. Gender considerations are particularly important within a global health perspective. Gender inequality is greatest in many resource-limited environments, and through disparities in resource allocation and access to health care and education, it often disproportionately affects women. Social determinants, including education and socioeconomic status, play an important role in the health and well-being of individuals at a population level and are themselves gendered.88. Heise L, Greene ME, Opper N, Stavropoulou M, Harper C, Nascimento M, et al. Gender inequality and restrictive gender norms: framing the challenges to health. Lancet. 2019;393:2440-54. This was evident in the study of Carpena et al., who found that education, skin color, and measures of wealth were associated with depression and suicidal ideation in women, but not men.33. Carpena MX, Costa FS, Martins-Silva T, Xavier MO, Loret de Mola C. Why Brazilian women suffer more from depression and suicidal ideation: a mediation analysis of the role of violence. Braz J Psychiatry. 2020 Jun 1;S1516-44462020005015201. doi: 10.1590/1516-4446-2019-0572. Online ahead of print.
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In general, this study provides further support for the significant public health concern of violence against women and the contribution of violence to depression and suicidal ideation. Women are at risk of exposure to gender-specific adverse experiences and environments that can negatively affect health and well-being (e.g., discrimination, child abuse or intimate partner violence). Many of these factors can co-occur simultaneously or over time, creating a cumulative burden that translates into health inequities over an individual’s life. Future research should incorporate measurement of specific types of violence across the lifespan, including child abuse, intimate partner violence and community violence. A coordinated approach to prevention and intervention addressing gender-based violence across societal, community and individual levels is needed.
References
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1Salk RH, Hyde JS, Abramson LY. Gender differences in depression in representative national samples: meta-analyses of diagnoses and symptoms. Psychol Bull. 2017;143:783-822.
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2Yu S. Uncovering the hidden impacts of inequality on mental health: a global study. Transl Psychiatry. 2018;8:98.
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3Carpena MX, Costa FS, Martins-Silva T, Xavier MO, Loret de Mola C. Why Brazilian women suffer more from depression and suicidal ideation: a mediation analysis of the role of violence. Braz J Psychiatry. 2020 Jun 1;S1516-44462020005015201. doi: 10.1590/1516-4446-2019-0572 Online ahead of print.
» 10.1590/1516-4446-2019-0572 -
4Niehoff D. Not hardwired: the complex neurobiology of sex differences in violence. Violence Gend. 2014;1:19-24.
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5Sacher J, Neumann J, Okon-Singer H, Gotowiec S, Villringer A. Sexual dimorphism in the human brain: evidence from neuroimaging. Magn Reson Imaging. 2013;31:366-75.
-
6Johnson JL, Greaves L, Repta R. Better science with sex and gender: facilitating the use of a sex and gender-based analysis in health research. Int J Equity Health. 2009;8:14.
-
7McCarthy KJ, Mehta R, Haberland NA. Gender, power, and violence: a systematic review of measures and their association with male perpetration of IPV. PLoS One. 2018;13:e0207091.
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8Heise L, Greene ME, Opper N, Stavropoulou M, Harper C, Nascimento M, et al. Gender inequality and restrictive gender norms: framing the challenges to health. Lancet. 2019;393:2440-54.
Publication Dates
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Publication in this collection
31 Aug 2020 -
Date of issue
Sep-Oct 2020
History
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Received
13 July 2020 -
Accepted
16 July 2020