(PS4-A13) Does Self-disgust Uniquely Characterize Sexual Assault-related PTSD?

Approximately 1 in 5 women are victims of sexual assault (Smith et al., 2018), and up to 48% of these individuals will develop PTSD as a result (Foa, 1997). Despite advances in the diagnosis and treatment of PTSD (Lancaster et al., 2016), up to one-third of individuals remain treatment resistant (Bryant, 2019), supporting the need for additional research into the development and maintenance of PTSD. Additional insight into the development of PTSD may require more consideration of the nature of the trauma. For example, sexual assault is an act in which one intentionally sexually touches another person without that person’s consent, or coerces or physically forces a person to engage in a sexual act against their will (Dworkin et al., 2017). Sexual assault may be viewed as a violation of the body envelope, and research has shown that violations of the body envelope often evoke disgust (Haidt et al., 1994). This response from the trauma victim may represent self-disgust that is defined as a strong distaste directed towards oneself or one’s actions (Overton et al., 2008). Although, self-disgust has been implicated in various disorders (Ille et al., 2014) including PTSD (Brake et al., 2017), it is unclear if self-disgust is characteristic of PTSD or merely a consequence of experiencing sexual assault. 

To address this research question, individuals who endorsed a sexual assault experience and met criteria for PTSD (PTSD+; n = 24), individuals who endorsed a sexual assault and did not meet criteria for PTSD (PTSD-; n = 22), and healthy controls (n = 21) completed the Mini International Neuropsychiatric Interview for DSM-5 (Sheehan et al., 2010) to determine diagnoses, the Self-Disgust Scale (Overton et al., 2008) and the PTSD Symptom Checklist for DSM-5 (PCL-5; Weathers et al., 2013). The sample was predominantly female (90%) and white (49%). 

A one-way analysis of variance (ANOVA) revealed significant differences in self-disgust for the PTSD+ group (M = 36.21, SD = 16.26), PTSD- group (M = 26.90, SD = 11.69), and healthy control group (M = 25.33, SD = 11.00), F(2,55) = 3.77, p = .029. A Fisher’s LSD post hoc test of multiple comparisons revealed that the PTSD+ group reported significantly higher levels of self-disgust than the PTSD- group (mean difference = 9.31, SE = 4.17, p = .03) and healthy control group (10.88, SE = 4.33, p = .015). Importantly, the PTSD- and healthy control groups did not significantly differ in reported levels of self-disgust (p > .10). Furthermore, within the PTSD+ group where self-disgust was the most significantly elevated, there was a strong, positive correlation between self-disgust and PTSD symptom severity (r = .66, p < .01).

The present study found significantly higher levels of self-disgust in the PTSD+ group compared to the healthy controls. The finding that self-disgust did not significantly differ between trauma-exposed individuals without PTSD and healthy controls suggests that self-disgust is uniquely linked with PTSD (rather than sexual trauma exposure per se.) For those that do develop PTSD as a result of a sexual assault, self-disgust also contributes signficant variance to the severity of PTSD symptoms. These findings highlight the need to incorporate self-disgust into theoretical models of the development and maintenance of PTSD.