Higher integration scores are associated with facial emotion perception differences in dissociative identity disorder

Dissociative Identity Disorder: A Review of Research From 2011 to 2021

ABSTRACT

Dissociative identity disorder (DID) has historically been one of the most controversial topics in the study of psychopathology. Building on a previous review of empirical research on DID from 2000 to 2010, the present review examined DID research from 2011 to 2021. The research output included 56 case studies and 104 empirical studies. Within the empirical studies, approximately 1354 new cases of DID emerged, which resulted in an average samples of approximately 20. Reanalysis of previous samples was standard in the literature with only 40% of reported cases being new. Studies emerged from dozens of countries across the world, but the majority of cases were from Western counties, especially the United States. Diagnosis primarily relied upon validated measures, but 74% of all new cases came from six research groups. Overall, research on DID is steady but methodologically limited in ways that make generalization, especially about etiology, difficult.

Posttraumatic stress symptom severity is associated with impaired processing of emotional faces in a large international sample

Trauma exposure and posttraumatic stress symptoms (PTSS) are associated with biases in emotional face processing. Existing research has utilized a variety of methodological techniques to demonstrate hyperreactivity to threatening cues in posttraumatic stress disorder (PTSD; i.e., fearful faces), but studies to date have shown conflicting findings, including both increased and decreased time fixating on fearful faces. Moreover, the impact of PTSS severity on emotional face processing in the general population is unknown, as the generalizability of prior work is limited. The current study aimed to examine the associations between PTSS and sensitivity to detecting differences in fearful, angry, and happy faces in a large international sample. Participants were 1,182 visitors (Mage = 31.13 years, SD = 13.57, range: 18-85 years) to TestMyBrain.org who completed three emotion sensitivity tasks and the PTSD Checklist for DSM-5. The results indicated that higher PTSS scores were associated with poorer performance in detecting happiness, fear, and anger, ps < .001, with the largest effect for fear, f 2 = .06, controlling for age and gender. Participants who experienced more recent and more direct trauma exposure displayed higher levels of PTSS, with a small but significant effect whereby more direct trauma exposure was associated with higher (i.e., better) scores for anger and fear, f2 s = .02. Women showed heightened sensitivity to detecting fear compared to men, d = 0.17. The present findings underscore the value of citizen science initiatives that allow researchers to obtain clinical data from diverse samples with a high degree of PTSS variability.