Sexual assault is an interpersonal trauma that causes significant distress and often challenges the survivor’s sense of control, safety, meaning, and perception of self and the world around them ^[1][2][1,2]. The physical, sexual, and psychological consequences of sexual victimization often have long-lasting effects on an individual’s well-being and future functioning [1]. Post-assault, many sexual assault survivors experience health outcomes such as injuries, sexually transmitted diseases, gynecological problems, depression, anxiety, or post-traumatic stress disorder (PTSD) ^[2][3][2,3]. Most research on sexual assault and PTSD reflects the experience of heterosexual women despite the wealth of empirical evidence demonstrating that sexual minorities are both at increased risk of sexual assault ^[4][5][6][4,5,6] and suffer greater mental and physical health disparities compared to heterosexuals [7]. Established risk factors for PTSD include gender, level of education, history and number of trauma exposures, previous mental disorders, and a history of exposure to interpersonal violence [8]. Several of these risk factors occur at higher rates among sexual and gender minorities, thereby highlighting the need for an exploration of the prevailing risks of PTSD following sexual assault within this population.

Sexual minorities are defined as individuals whose sexual orientation and sexual practices differ from heterosexuals, including lesbian, gay, bisexual, or pansexual people [9]. Individuals who identify as a sexual minority are at greater risk of sexual victimization than individuals who identify as heterosexuals ^[10][11][10,11] in both childhood and adulthood [12]. According to the US-based National Intimate Partner and Sexual Violence Survey (NISVS) [13], while all lesbian, gay, and bisexual (LGB) individuals are at a greater risk of experiencing sexual assault than individuals who identify as heterosexuals, there are notable variances among subgroups. The NISVS reported that 46% of lesbians and 75% of bisexual women experienced sexual assault during their lifetime, while 40% of gay men and 47% of bisexual men were sexually victimized [13]. Sexual minority men are at greater risk of experiencing rape than heterosexual men [4]. Bisexual women were the highest risk group for sexual victimization by any type of perpetrator, including intimate partners [13].

2. Post-Traumatic Stress Disorder and Sexual Assault

The Diagnostic and Statistical Manual V (DSM 5) characterizes PTSD by a range of criteria, beginning with exposure to or experiencing actual or threatened death, serious injury, or sexual victimization ^[14][16]. The effects of PTSD are persistent and long-lasting, and impact multiple areas of functioning ^[14][16]. PTSD is precipitated by various risk factors such as a “female sex, childhood trauma, fewer years of schooling, prior mental disorders, exposure to four or more traumatic events, and a history of exposure to interpersonal violence” [8]. The intensity of trauma exposure, and the lack of control and unpredictability of the event, are also believed to influence the development of PTSD [8], and the experience of sexual assault is a type of traumatic event that is characterized by an imbalance of power and control [1]. Negative mental health outcomes are common among all survivors of sexual assault (regardless of sexual orientation), and psychopathology is present in various diagnostic categories [3]. Sexual assault is considered the highest predictive risk factor for PTSD ^[15][16][18,19], and PTSD is one of the most frequent diagnoses among survivors of sexual trauma ^[1][2][17][1,2,20]. In the first two weeks following a sexual assault, nearly all survivors (94%) experience PTSS, which includes nightmares, flashbacks, intrusive thoughts, dissociation, affect dysregulation, substance use, and suicidality ^[18][21]. These symptoms typically abate in approximately half of sexual assault survivors within a three-month period, while 47% will continue to experience one or more symptoms of PTSD three months post-assault. The severity of symptoms fluctuates over time and may be influenced by additional stressors or life events [8]. Research exploring PTSD following sexual assault among sexual minorities is limited. However, Kerridge et al. [10] found that lesbian, gay, and bisexual (LGB) individuals are at a significantly greater risk of developing PTSD in their lifetime than heterosexuals. Specifically, female bisexuals were three times more likely to develop PTSD. Similarly, lesbian women (12.1%), gay men (7.8%), and male bisexuals (11.1%) were at increased risk [10]. These findings are consistent with Lehavot and Simpson ^[19][22], who explored the experience of trauma and PTSD in lesbian and bisexual (LB) veterans. They found that veterans who identified as lesbian or bisexual experienced high rates of PTSD and depression that were exacerbated by a sexist and discriminatory environment.

3. Minority Stress Theory

Minority stress theory is a useful framework to explore the unique compounding risk factors of PTSS and PTSD for sexual minorities following sexual assault. Minority stress theory hypothesizes that: (1) members of disadvantaged social groups are exposed to more stress than members of advantaged groups, and (2) as a result, they suffer from more mental health disorders ^[7][20][7,23]. For decades, minority stress theory has been widely utilized to account for the significant physical and mental health disparities of sexual minorities ^[11][21][11,24] and its central tenets continue to have relevance today ^[22][25]. Minority stress posits that the prejudice, stigma, and discrimination directed toward members of socially disadvantaged groups, such as sexual minorities, bring about unique stressors and that these stressors cause adverse health outcomes, including mental health disorders ^[7][22][7,25]. Individuals who identify as a sexual minority face considerable public scrutiny relative to their sexual identity, influencing an internalized self-perception as devalued and stigmatized ^[20][23]. Furthermore, the daily stressors of living in a heterosexist society compound existing stressors and erode coping mechanisms, ultimately negatively impacting health and well-being ^[23][26]. According to Frost and Meyer ^[22][25], stigma-related stress precipitates emotion dysregulation and interpersonal difficulties that may pose an increased risk for mental health disparities.

4. Risk of PTSS and PTSD for Sexual Minority Survivors of Sexual Assault

A History of Trauma

The risk of post-traumatic symptomatology is heightened with previous exposure to a traumatic event ^[24][27]. Sexual minorities experience elevated rates of childhood sexual abuse compared to individuals who are heterosexual ^[25][26][27][28,29,30]. Furthermore, adolescence is a time when sexual minorities are especially vulnerable to sexual violence ^[28][31]. Childhood sexual abuse is a particularly strong risk factor for sexual revictimization ^[29][30][32,33]. A meta-analysis examining the rate of sexual revictimization found that nearly half (47.9%) of all child sexual abuse survivors experience subsequent sexual assaults in their lifetime ^[29][30][32,33]. Previous trauma experiences are associated with poor perceived health ^[31][37] and the development and severity of PTSS/PTSD ^[32][33][34,36]. The development of PTSD is associated with a dose-response, whereby increasing exposure to trauma increases the severity of symptoms ^[34][38]. Individuals who identify as LGBTQ+ have an elevated risk of trauma exposure and minority stress ^[35][36][37][39,40,41], largely based on increased rates of discrimination and victimization enacted in a heteronormative society ^[37][38][41,42]. Sexual and gender minorities experience heightened traumatic exposure and stress throughout their lifespan, including physical and sexual violence ^[37][39][41,43], child maltreatment ^[37][40][41,44], harassment and discrimination ^[38][40][42,44], isolation, and rejection by family and friends ^[35][39].

5. History of Mental Health Disorders

Prior mental health disorders are predictive of an increased risk of PTSS and PTSD ^{[8][15][24][32]}[8,18,27,34]. Sexual minorities suffer from worse mental health outcomes than their heterosexual counterparts, including substance use disorders, affective disorders, and suicidal behavior ^[7][41][42][7,45,46]. For example, decades of research have established that LGB individuals are at much higher risk of substance use disorders than individuals who identify as heterosexuals ^[43][44][45][14,15,47]. Studies indicate that LGB youth are at 190% higher risk than individuals who identify as heterosexuals for substance use disorders, with subgroups such as bisexuals and females reflecting exceptionally elevated rates (340% and 400% respectively). Compared to heterosexuals, sexual minorities face disproportionately higher rates of mental health disparities that are compounded by socially stigmatizing living conditions and minority stress ^[41][45]. Keating and Muller ^[38][42] posit that LGBTQ+ individuals who attribute their trauma to discrimination are more likely than individuals who experience non-discrimination-related traumas to experience PTSS. 

6. Lack of Support

Lack of social support following a traumatic event is a risk factor for PTSS and PTSD ^[24][27]. Following a sexual assault, many heterosexual survivors seek out family, friends, and intimate partners as instinctual safe zones. When these disclosures are responded to empathically, the survivor may choose to disclose their victimization to a variety of community responders, including healthcare providers, social services, and the criminal justice system ^[46][50]. Motivations for disclosure are often associated with seeking social support, professional treatment, or strengthening interpersonal bonds ^[47][51]. The importance of the disclosure experience cannot be understated, as the type of response survivors receive following a sexual assault disclosure can significantly impact their recovery trajectories, either supporting or inhibiting the healing process ^[48][49][52,53]. The lack of support that survivors experience due to negative responses to sexual assault disclosures (e.g., victim blaming, stigma) is strongly associated with PTSS following a sexual assault ^[50][51][54,55]. Disbelief, blame, or dismissiveness during sexual assault disclosures reinforces societal adherence to rape myths and may reinforce survivors’ feelings of shame ^[51][55]. When sexual assault survivors report the assault and receive negative reactions or disbelief, they are unlikely to disclose subsequent sexual victimization ^[49][53] or seek out additional formal support services ^[52][56]. Minority stress theory posits that sexual minorities experience significant discrimination, leading to heightened experiences of stress [7]. Furthermore, dominant sexual and gender scripts accepted in the general public view sexual assault through a heteronormative lens whereby men are perpetrators and women are victims ^[53][60]. This narrow perception of the occurrence of sexual assault poses challenges for sexual minority individuals to attain support. Expectations of negative disclosure experiences may place sexual minorities at greater risk of developing PTSS, as they are prone to anticipate and expect rejection from society and may refrain from seeking support post-assault [7].  Moreover, in a qualitative study of sexual minority men who have experienced sexual assault, men consistently indicated that they expected to encounter discrimination and disbelief if they disclosed sexual assault. Their expectations led many male survivors to refrain from disclosing sexual assault and this contributed to an increase in their traumatic response ^[52][56].

7. Interpersonal Violence: Stigma and Internalized Homophobia

Interpersonal violence is a predictive risk factor for PTSD [8] and homophobia is a form of gender-based interpersonal violence ^[54][62]. Consistent with minority stress theory, sexual minorities are likely to experience the stress of compounding stigma following a sexual assault due to the victim-blaming messages they receive from society as a whole, as well as the internalization of socially sanctioned homophobia ^{[7][44][55][56]}[7,15,63,64]. Defined as “a set of negative attitudes and affects toward homosexuality in other persons and toward homosexual features in oneself” ^[57][65], internalized homophobia occurs when the individual accepts and internalizes the negative stereotypes and myths about homosexuality that persist throughout mainstream culture ^[58][66]. The stigma and discrimination that sexual minority individuals experience is compounded following a sexual assault. Research regarding bisexual women’s vulnerabilities and consequences of sexual assault point to several ecological factors, including “a cultural milieu prone to hypersexualization, objectification, and dehumanization; … stereotypical understandings of bisexuality in women that may engender negative appraisals and resulting aggression toward this group” ^[43][14]. There is a growing body of research that suggests that bisexual women experience minority stress and more severe adverse health outcomes because they are doubly stigmatized and marginalized from both heterosexual and gay/lesbian communities due to strongly held stereotypes and societal perceptions ^[25][28].  Lesbian women are also at risk of experiencing compounding stigma and stereotyping post-assault ^[7][25][7,28]. This social stigma contributes to internalized homophobia. The experience of internalized homophobia is correlated with concealment strategies whereby the sexual minority individual does not disclose their sexual orientation as a survival strategy ^[59][67]. Lesbian women who have been victimized by another woman may experience compounding stress as disclosure of the assault may necessitate coming out or, conversely, further increasing their avoidance and concealment strategies [7].

8. Conclusions

Sexual and gender minorities experience sexual assault at a higher rate than their heterosexual counterparts and PTSS and PTSD are common adverse health outcomes of sexual violence. Several risk factors have been associated with PTSS and PTSD, all of which are prevalent among individuals who identify as a sexual or gender minority. Thus, with an increased risk for PTSD, and heightened rates of sexual violence among the LGBTQ+ population, further research is needed to empirically explore the conferring risks for PTSD among sexual and gender minorities.