PTSD outcomes (n = 33)

Studies examining MST dichotomously (as an umbrella term for a range of behaviours) found associations with probable PTSD (Blais, Livingston, Barrett, & Tannahill, Reference Blais, Livingston, Barrett and Tannahill2023; Fontana & Rosenheck, Reference Fontana and Rosenheck1998; Gibson et al., Reference Gibson, Maguen, Xia, Barnes, Peltz and Yaffe2019; Himmelfarb, Yaeger, & Mintz, Reference Himmelfarb, Yaeger and Mintz2006; Kimerling et al., Reference Kimerling, Street, Pavao, Smith, Cronkite, Holmes and Frayne2010; Kimerling, Gima, Smith, Street, & Frayne, Reference Kimerling, Gima, Smith, Street and Frayne2007; Lindsay et al., Reference Lindsay, Keo-Meier, Hudson, Walder, Martin and Kauth2016; Maguen et al., Reference Maguen, Cohen, Ren, Bosch, Kimerling and Seal2012; Yaeger, Himmelfarb, Cammack, & Mintz, Reference Yaeger, Himmelfarb, Cammack and Mintz2006; Zelkowitz, Sienkiewicz, Vogt, Smith, & Mitchell, Reference Zelkowitz, Sienkiewicz, Vogt, Smith and Mitchell2022) and higher PTSD symptom scores (Banducci, McCaughey, Gradus, & Street, Reference Banducci, McCaughey, Gradus and Street2019; Blais et al., Reference Blais, Livingston, Barrett and Tannahill2023; Cobb Scott et al., Reference Cobb Scott, Pietrzak, Southwick, Jordan, Silliker, Brandt and Haskell2014; Decker et al., Reference Decker, Ramsey, Ronzitti, Kerns, Driscoll, Dziura, Skanderson, Bathulapalli, Brandt, Haskell and Goulet2021; Dutra et al., Reference Dutra, Grubbs, Greene, Trego, McCartin, Kloezeman and Morland2011; Esopenko et al., Reference Esopenko, De Souza, Wilde, Dams-O’Connor, Teng and Menefee2023; Luterek, Bittinger, & Simpson, Reference Luterek, Bittinger and Simpson2011; Mercado, Ming Foynes, Carpenter, & Iverson, Reference Mercado, Ming Foynes, Carpenter and Iverson2015; Murdoch et al., Reference Murdoch, Polusny, Hodges, Cowper, Murdoch, Polusny, Hodges and Cowper2006; Murray-Swank, Dausch, & Ehrnstrom, Reference Murray-Swank, Dausch and Ehrnstrom2018; Rønning et al., Reference Rønning, Shor, Anyan, Hjemdal, Jakob Bøe, Dempsey and Espetvedt Nordstrand2024; Wolfe et al., Reference Wolfe, Sharkansky, Read, Dawson, Martin and Ouimette1998) across intrusion, avoidance, cognitive/mood, and hyperarousal symptom clusters (Mahoney, Shayani, & Iverson, Reference Mahoney, Shayani and Iverson2024).

When MST subtypes were examined, MSA more consistently predicted greater PTSD severity (Gorman et al., Reference Gorman, Kearns, Pantalone, Bovin, Keane and Marx2021; Gross et al., Reference Gross, Cunningham, Moore, Naylor, Brancu, Wagner, Elbogen, Calhoun and Kimbrel2018; Luterek et al., Reference Luterek, Bittinger and Simpson2011; Wolfe et al., Reference Wolfe, Sharkansky, Read, Dawson, Martin and Ouimette1998; Zerach, Reference Zerach2023) and probable PTSD (Street, Stafford, Mahan, & Hendricks, Reference Street, Stafford, Mahan and Hendricks2008) than MSH (Blais, Brignone, Fargo, Livingston, & Andresen, Reference Blais, Brignone, Fargo, Livingston and Andresen2019; Kang, Dalager, Mahan, & Ishii, Reference Kang, Dalager, Mahan and Ishii2005; Street et al., Reference Street, Stafford, Mahan and Hendricks2008; Surís, Lind, Kashner, Borman, & Petty, Reference Surís, Lind, Kashner, Borman and Petty2004), though MSH was linked to probable PTSD in two studies (Hendrikx, Williamson, & Murphy, Reference Hendrikx, Williamson and Murphy2023; Kang et al., Reference Kang, Dalager, Mahan and Ishii2005). In a study stratified by sexual orientation, MSA increased PTSD symptom severity in the heterosexual sample (Gorman et al., Reference Gorman, Kearns, Pantalone, Bovin, Keane and Marx2021), with the small sexual minority sub-sample perhaps lacking statistical power to detect an association. Four studies reported no association between MSA and probable PTSD (Gorman et al., Reference Gorman, Kearns, Pantalone, Bovin, Keane and Marx2021; Hendrikx et al., Reference Hendrikx, Williamson and Murphy2023; Kearns et al., Reference Kearns, Gorman, Bovin, Green, Rosen, Keane and Marx2016; Moreau et al., Reference Moreau, Duron, Bedretdinova, Bohet, Panjo, Bajos and Meynard2022) and severity (Kearns et al., Reference Kearns, Gorman, Bovin, Green, Rosen, Keane and Marx2016).

Interpersonal support appeared to influence these associations. During deployment, reduced interpersonal support from military networks (Laws, Mazure, McKee, Park, & Hoff, Reference Laws, Mazure, McKee, Park and Hoff2016; Webermann et al., Reference Webermann, Relyea, Portnoy, Martino, Brandt and Haskell2023) mediated links with PTSD symptoms, and concerns surrounding relationships at home exacerbated the impact of MST on PTSD severity (Banducci et al., Reference Banducci, McCaughey, Gradus and Street2019). Post-deployment, detriments to non-military networks mediated the association between MST and PTSD symptoms (Fontana & Rosenheck, Reference Fontana and Rosenheck1998; Smith, Brady, Hammer, Carlson, & Mohr, Reference Smith, Brady, Hammer, Carlson and Mohr2020; Smith, Wang, Vaughn-Coaxum, Di Leone, & Vogt, Reference Smith, Wang, Vaughn-Coaxum, Di Leone and Vogt2017; Webermann et al., Reference Webermann, Relyea, Portnoy, Martino, Brandt and Haskell2023), and intimate partner violence (IPV) experiences mediated the association between MST and PTSD-avoidance and PTSD-negative cognitions/mood symptoms (Mahoney et al., Reference Mahoney, Shayani and Iverson2024).

Compared to other traumas, MST predicted higher risk of PTSD (Blais et al., Reference Blais, Livingston, Barrett and Tannahill2023) and symptom severity (Surís et al., Reference Surís, Lind, Kashner, Borman and Petty2004) than civilian sexual assault. Comparisons of perpetrator identity (MST perpetrated by intimate partners versus perpetrators who were not intimate partners) revealed no significant differences (Mercado et al., Reference Mercado, Ming Foynes, Carpenter and Iverson2015), suggesting perpetrator identity cannot explain these differences. Considered alongside other trauma exposures, MST and IPV cumulatively predicted higher PTSD symptoms (Esopenko et al., Reference Esopenko, De Souza, Wilde, Dams-O’Connor, Teng and Menefee2023). Although one study did not find an interaction between MSA and combat exposure in PTSD symptom severity (Gross et al., Reference Gross, Cunningham, Moore, Naylor, Brancu, Wagner, Elbogen, Calhoun and Kimbrel2018), another study found MST interacted with combat exposure to increase combat-related PTSD symptoms (Cobb Scott et al., Reference Cobb Scott, Pietrzak, Southwick, Jordan, Silliker, Brandt and Haskell2014), suggesting MST may exacerbate existing vulnerabilities.

This review found limited evidence linking MST and Complex PTSD (CPTSD) (Luterek et al., Reference Luterek, Bittinger and Simpson2011; Zerach, Reference Zerach2023). CPTSD, characterized by PTSD symptoms plus affective dysregulation, negative self-concept and relationship disturbances, often arises from prolonged or repeated trauma exposure (Herman, Reference Herman1992) and may be influenced by additional factors.

Depression outcomes (n = 23)

Most studies reported associations with MST and probable depression (Gibson et al., Reference Gibson, Maguen, Xia, Barnes, Peltz and Yaffe2019; Gorman et al., Reference Gorman, Kearns, Pantalone, Bovin, Keane and Marx2021; Gradus, Street, Kelly, & Stafford, Reference Gradus, Street, Kelly and Stafford2008; Kearns et al., Reference Kearns, Gorman, Bovin, Green, Rosen, Keane and Marx2016; Kimerling et al., Reference Kimerling, Street, Pavao, Smith, Cronkite, Holmes and Frayne2010; Maguen et al., Reference Maguen, Cohen, Ren, Bosch, Kimerling and Seal2012; Moreau et al., Reference Moreau, Duron, Bedretdinova, Bohet, Panjo, Bajos and Meynard2022; Rønning et al., Reference Rønning, Shor, Anyan, Hjemdal, Jakob Bøe, Dempsey and Espetvedt Nordstrand2024) and higher symptom severity (Blais et al., Reference Blais, Livingston, Barrett and Tannahill2023; Gorman et al., Reference Gorman, Kearns, Pantalone, Bovin, Keane and Marx2021; Kearns et al., Reference Kearns, Gorman, Bovin, Green, Rosen, Keane and Marx2016; Murray-Swank et al., Reference Murray-Swank, Dausch and Ehrnstrom2018). Null findings from a small, high-risk-of-bias study in US serving women (Dutra et al., Reference Dutra, Grubbs, Greene, Trego, McCartin, Kloezeman and Morland2011) and in study with sexual minority US ex-servicewomen (Gorman et al., Reference Gorman, Kearns, Pantalone, Bovin, Keane and Marx2021) may have reflected low statistical power.

When MST sub-types were examined separately, MSA predicted probable depression (Blais et al., Reference Blais, Brignone, Fargo, Livingston and Andresen2019; Gibson et al., Reference Gibson, Maguen, Xia, Barnes, Peltz and Yaffe2019; Gross, Kroll-Desrosiers, & Mattocks, Reference Gross, Kroll-Desrosiers and Mattocks2020; Hankin et al., Reference Hankin, Skinner, Sullivan, Miller, Frayne and Tripp1999; Skinner et al., Reference Skinner, Kressin, Frayne, Tripp, Hankin, Miller and Sullivan2000; Street et al., Reference Street, Stafford, Mahan and Hendricks2008) and higher depression severity more consistently than MSH (Blais et al., Reference Blais, Brignone, Fargo, Livingston and Andresen2019). Religious service attendance buffered the impacts of MSA on depression in one study with US ex-servicewomen (Chang, Skinner, & Boehmer, Reference Chang, Skinner and Boehmer2001).

Compared with interpersonal trauma experienced outside of military service, MST was associated with higher depression severity (Newins et al., Reference Newins, Glenn, Wilson, Wilson, Kimbrel, Beckham, Workgroup and Calhoun2021) but not higher risk of probable depression (Blais et al., Reference Blais, Livingston, Barrett and Tannahill2023). Comparisons of perpetrator identities (intimate partners versus not intimate partners) revealed no significant differences in depressive symptoms (Mercado et al., Reference Mercado, Ming Foynes, Carpenter and Iverson2015). Two studies suggested that cumulative exposures (e.g. non-military sexual trauma) (Blais et al., Reference Blais, Livingston, Barrett and Tannahill2023) and IPV (Esopenko et al., Reference Esopenko, De Souza, Wilde, Dams-O’Connor, Teng and Menefee2023) alongside MST may elevate depression risk (Blais et al., Reference Blais, Livingston, Barrett and Tannahill2023) and symptom severity (Esopenko et al., Reference Esopenko, De Souza, Wilde, Dams-O’Connor, Teng and Menefee2023).

Anxiety outcomes (n = 8)

Five studies reported significant associations between MST and probable anxiety (Gibson et al., Reference Gibson, Maguen, Xia, Barnes, Peltz and Yaffe2019; Kimerling et al., Reference Kimerling, Street, Pavao, Smith, Cronkite, Holmes and Frayne2010; Maguen et al., Reference Maguen, Cohen, Ren, Bosch, Kimerling and Seal2012; Murray-Swank et al., Reference Murray-Swank, Dausch and Ehrnstrom2018; Sumner et al., Reference Sumner, Lynch, Viernes, Beckham, Coronado, Dennis and Ebrahimi2021) and one with higher anxiety symptom severity (Rønning et al., Reference Rønning, Shor, Anyan, Hjemdal, Jakob Bøe, Dempsey and Espetvedt Nordstrand2024). One study found that this relationship lost significance when adjusting for age and race (Kimerling et al., Reference Kimerling, Gima, Smith, Street and Frayne2007) and another found no association in a sample of US transgender ex-servicewomen (Lindsay et al., Reference Lindsay, Keo-Meier, Hudson, Walder, Martin and Kauth2016), highlighting the potential influence of demographic factors.

Suicidality outcomes (n = 17)

Most studies reported associations between MST and suicidality (Murray-Swank et al., Reference Murray-Swank, Dausch and Ehrnstrom2018), including suicidal behaviours (Wilson et al., Reference Wilson, Newins, Wilson, Elbogen, Dedert, Calhoun, Beckham, Workgroup and Kimbrel2020) and ideation (Blais et al., Reference Blais, Brignone, Fargo, Livingston and Andresen2019; Blais et al., Reference Blais, Livingston, Barrett and Tannahill2023; Blais & Geiser, Reference Blais and Geiser2019; Decker et al., Reference Decker, Ramsey, Ronzitti, Kerns, Driscoll, Dziura, Skanderson, Bathulapalli, Brandt, Haskell and Goulet2021; Esopenko et al., Reference Esopenko, De Souza, Wilde, Dams-O’Connor, Teng and Menefee2023; Gibson et al., Reference Gibson, Maguen, Xia, Barnes, Peltz and Yaffe2019; Gradus, King, Galatzer-Levy, & Street, Reference Gradus, King, Galatzer-Levy and Street2017; Gross et al., Reference Gross, Kroll-Desrosiers and Mattocks2020; Hoffmire et al., Reference Hoffmire, Monteith, Denneson, Holliday, Park, Mazure and Hoff2021; Stefanovics, Potenza, Tsai, Nichter, & Pietrzak, Reference Stefanovics, Potenza, Tsai, Nichter and Pietrzak2023). Both MSH and MSA increased risk of suicidal ideation (Gross et al., Reference Gross, Kroll-Desrosiers and Mattocks2020; Monteith et al., Reference Monteith, Kittel, Schneider, Miller, Holliday, Katon, Brenner and Hoffmire2023), with MSA more consistently reported as a predictor (Blais et al., Reference Blais, Brignone, Fargo, Livingston and Andresen2019; Monteith et al., Reference Monteith, Kittel, Schneider, Miller, Holliday, Katon, Brenner and Hoffmire2023). One study identified depressive symptom severity and PTSD-related anhedonia as mediators in the association between MSA and suicidal ideation. No significant pathways were observed for MSH (Blais & Geiser, Reference Blais and Geiser2019), indicating potentially distinct mechanisms.

Comparisons of MST with other interpersonal traumas did not find unique effects of MST. MSA was associated with suicidal ideation in US serving and ex-servicewomen, but this association did not differ significantly from civilian adulthood sexual assault (Newins et al., Reference Newins, Glenn, Wilson, Wilson, Kimbrel, Beckham, Workgroup and Calhoun2021). Similarly, suicidal ideation and behaviour did not differ among US ex-servicewomen who had experienced MST only, IPV only, or both MST and IPV (Esopenko et al., Reference Esopenko, De Souza, Wilde, Dams-O’Connor, Teng and Menefee2023).

One study with university-enrolled US serving and ex-servicewomen did not identify an association between MST and suicidality (Bryan, Bryan, & Clemans, Reference Bryan, Bryan and Clemans2015), perhaps reflecting potentially distinct support resources available to participants in this sample. Accordingly, another study found that perceived post-deployment support mediated the relationship between deployment MST and suicidal ideation (Monteith et al., Reference Monteith, Hoffmire, Holliday, Park, Mazure and Hoff2018). Together, findings implicate psychological distress and access to social support as influential in the relationship between MST and suicidality.

Harmful substance use outcomes (n = 11)

Most studies observed associations between MST and probable harmful substance use (Gibson et al., Reference Gibson, Maguen, Xia, Barnes, Peltz and Yaffe2019; Hankin et al., Reference Hankin, Skinner, Sullivan, Miller, Frayne and Tripp1999; Kimerling et al., Reference Kimerling, Street, Pavao, Smith, Cronkite, Holmes and Frayne2010; Maguen et al., Reference Maguen, Cohen, Ren, Bosch, Kimerling and Seal2012; Surís, Lind, Kashner, & Borman, Reference Surís, Lind, Kashner and Borman2007; Yalch, Hebenstreit, & Maguen, Reference Yalch, Hebenstreit and Maguen2018), as well as greater symptom severity (Yalch et al., Reference Yalch, Hebenstreit and Maguen2018). Two studies identified PTSD (Banducci et al., Reference Banducci, McCaughey, Gradus and Street2019) and depression (Gradus et al., Reference Gradus, Street, Kelly and Stafford2008) symptoms as potential mediators of this relationship. One small study did not find an association between MST and past year alcohol problems in US serving women (Fillo, Goodell, Homish, & Homish, Reference Fillo, Goodell, Homish and Homish2023), perhaps reflecting limited statistical power.

Studies found MSA was more consistently associated with MSA than MSH. Specifically, MSA (but not MSH) predicted harmful alcohol use in UK ex-servicewomen (Hendrikx et al., Reference Hendrikx, Williamson and Murphy2023) and was associated with both higher harmful alcohol use scores and risk for harmful alcohol use in US ex-servicewomen (Surís et al., Reference Surís, Lind, Kashner and Borman2007). Despite positive associations between higher MST frequency and alcohol use severity (Banducci et al., Reference Banducci, McCaughey, Gradus and Street2019), one study found high exposure to any military stressors increased probable substance use disorder (SUD) risk, whilst exposure to MSA alone was associated with higher SUD symptoms but not greater SUD risk (Yalch et al., Reference Yalch, Hebenstreit and Maguen2018). Taken together, findings suggest that trauma exposure generally, rather than MST itself, may influence substance use.

Disordered eating outcomes (n = 5)

Findings related to MST and disordered eating were mixed. Two studies found that MST was associated with probable eating disorders in US ex-servicewomen (Breland, Donalson, Dinh, & Maguen, Reference Breland, Donalson, Dinh and Maguen2018) and with a comorbid eating disorder amongst those with PTSD (Maguen et al., Reference Maguen, Cohen, Ren, Bosch, Kimerling and Seal2012). The role of PTSD in this association remained unclear. One high-risk-of-bias study found PTSD mediated the relationship between MSA with bulimia nervosa and food preoccupation symptoms in US ex-servicewomen (Sandhu, Dougherty, & Haedt-Matt, Reference Sandhu, Dougherty and Haedt-Matt2022). Contrastingly, another study did not find a mediating role of PTSD, but suggested an indirect pathway via shape and weight concerns (Zelkowitz et al., Reference Zelkowitz, Sienkiewicz, Vogt, Smith and Mitchell2022). In US serving women, psychological distress fully mediated the relationship between MST and disordered eating symptoms (Harned & Fitzgerald, Reference Harned and Fitzgerald2002), with the focus on recent workplace MST potentially reflecting a unique context where participants may have remained in contact with perpetrators.

General mental health and functioning outcomes (n = 10)

Findings indicated that MST negatively impacted general mental health in both serving (Harned, Ormerod, Palmieri, Collinsworth, & Reed, Reference Harned, Ormerod, Palmieri, Collinsworth and Reed2002; Kim, Lee, Lee, Han, & Park, Reference Kim, Lee, Lee, Han and Park2017) and ex-servicewomen (Mercado et al., Reference Mercado, Ming Foynes, Carpenter and Iverson2015; Skinner et al., Reference Skinner, Kressin, Frayne, Tripp, Hankin, Miller and Sullivan2000), with one study observing greater negative impacts of MST than non-military sexual assault (Surís et al., Reference Surís, Lind, Kashner and Borman2007). Religious service attendance was identified as a potential protective factor (Chang et al., Reference Chang, Skinner and Boehmer2001). With regards to somatic symptoms specifically, a positive association with MST was observed in US ex-servicewomen (Murray-Swank et al., Reference Murray-Swank, Dausch and Ehrnstrom2018), with MSH and MSA each identified as predictors (Street et al., Reference Street, Stafford, Mahan and Hendricks2008). Contrastingly, only MSH was associated with high physical somatisation in UK ex-servicewomen (Hendrikx et al., Reference Hendrikx, Williamson and Murphy2023).

Other psychiatric conditions (n = 4)

MST was associated with impulse-control disorders, dissociative disorders, bipolar disorder (Kimerling et al., Reference Kimerling, Gima, Smith, Street and Frayne2007; Sumner et al., Reference Sumner, Lynch, Viernes, Beckham, Coronado, Dennis and Ebrahimi2021), and personality disorders (Sumner et al., Reference Sumner, Lynch, Viernes, Beckham, Coronado, Dennis and Ebrahimi2021) in US ex-servicewomen. In one study with transgender US ex-servicewomen, MST predicted bipolar disorder and personality disorder but not schizophrenia (Lindsay et al., Reference Lindsay, Keo-Meier, Hudson, Walder, Martin and Kauth2016).

Mental health impacts

MST was linked to a range of mental health symptoms, including depression (Reinhardt, McCaughey, Vento, & Street, Reference Reinhardt, McCaughey, Vento and Street2023) and PTSD (Brownstone, Gerber, Holliman, & Monteith, Reference Brownstone, Gerber, Holliman and Monteith2018) (Katz, Huffman, & Cojucar, Reference Katz, Huffman and Cojucar2017; Reinhardt et al., Reference Reinhardt, McCaughey, Vento and Street2023). Anxiety was linked to safety concerns around people and revictimisation fears (Katz et al., Reference Katz, Huffman and Cojucar2017; Reinhardt et al., Reference Reinhardt, McCaughey, Vento and Street2023), leading to isolation (Reinhardt et al., Reference Reinhardt, McCaughey, Vento and Street2023). Suicidal ideation and attempts appeared linked to difficulty coping with MST-related distress (Katz et al., Reference Katz, Huffman and Cojucar2017; Reinhardt et al., Reference Reinhardt, McCaughey, Vento and Street2023). Whilst some participants experienced posttraumatic growth (Katz et al., Reference Katz, Huffman and Cojucar2017; Reinhardt et al., Reference Reinhardt, McCaughey, Vento and Street2023), this appeared contingent on mental healthcare or effective social support.

Maladaptive coping

Motivations to escape distressing symptoms (Brownstone et al., Reference Brownstone, Gerber, Holliman and Monteith2018) appeared to promote risky behaviours like reckless driving (Brownstone et al., Reference Brownstone, Gerber, Holliman and Monteith2018; Reinhardt et al., Reference Reinhardt, McCaughey, Vento and Street2023), physical altercations (Reinhardt et al., Reference Reinhardt, McCaughey, Vento and Street2023), and risky sexual behaviours (Brownstone et al., Reference Brownstone, Gerber, Holliman and Monteith2018; Reinhardt et al., Reference Reinhardt, McCaughey, Vento and Street2023). Disordered eating (Brownstone et al., Reference Brownstone, Gerber, Holliman and Monteith2018) and substance use (Katz et al., Reference Katz, Huffman and Cojucar2017; Reinhardt et al., Reference Reinhardt, McCaughey, Vento and Street2023) also emerged as coping methods, with levels of substance use described as proportional to the salience of negative memories (Reinhardt et al., Reference Reinhardt, McCaughey, Vento and Street2023).

Negative changes to self-perception

Self-blame was linked to disordered eating aimed at weight gain to prevent sexual attention (Reinhardt et al., Reference Reinhardt, McCaughey, Vento and Street2023). Self-blame and feelings of powerlessness (Brownstone et al., Reference Brownstone, Gerber, Holliman and Monteith2018; Reinhardt et al., Reference Reinhardt, McCaughey, Vento and Street2023) also related to disordered eating through lowered self-esteem, including body dissatisfaction (Brownstone et al., Reference Brownstone, Gerber, Holliman and Monteith2018).

Support from others is important for mental health

Although social support emerged as beneficial for coping with poor mental health (Brownstone et al., Reference Brownstone, Gerber, Holliman and Monteith2018; Katz et al., Reference Katz, Huffman and Cojucar2017), decreased interpersonal trust (Reinhardt et al., Reference Reinhardt, McCaughey, Vento and Street2023) appeared to prevent engagement with informal networks. Participants in one study reported positive psychotherapy treatment experiences (Katz et al., Reference Katz, Huffman and Cojucar2017), however, evidence was limited by potential bias arising from participants via the psychotherapy service.