Although dissociative identity disorder (DID), the most severe of the dissociative disorders, has retained its own diagnostic entity since its introduction in the DSM-III, cases of DID are rarely seen in South and East Asia, likely due to the higher prevalence of possession disorder. We report two patients with DID who were recently admitted to our inpatient psychiatric unit and demonstrated distinct transitions to several identities. Their diagnoses were confirmed through a structured interview for dissociative disorders and possible differential diagnoses were ruled out by psychological, neuroimaging, and laboratory tests. The rapid transition to a Westernized, individualized society along with an increase in child abuse, might contribute to an increase in DID, previously under-diagnosed in this region.
Asia ; Child ; Child Abuse ; Diagnosis ; Diagnosis, Differential ; Diagnostic and Statistical Manual of Mental Disorders ; Dissociative Disorders ; Far East ; Humans ; Inpatients ; Korea* ; Multiple Personality Disorder ; Neuroimaging ; Prevalence

Objective: This study aimed to investigate the validity and reliability of the Korean version of the Brief Irritability Test (BITe) and adapt it for Korean patients with psychiatric disorders. Methods: A total of 296 patients at the Department of Psychiatry of Hanyang University Guri Hospital completed the BITe, Korean Beck Depression Inventory-II, Korean Beck Anxiety Inventory, the Korean version of the State-Trait Anger Expression Inventory, and Barratt Impulsiveness Scale-11. Construct validity was confirmed through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Reliability testing included assessments of internal consistency (Cronbach’s α) and item-total correlations. Convergent validity was examined through correlational analyses with variables such as anxiety, depression, anger, and impulsivity. Results: First, the scale had good internal consistency with a Cronbach’s α of 0.88. Second, EFA indicated a single dimensionality of the BITe, and CFA demonstrated a reasonable fit for the single-factor model (comparative fit index=0.97, Tucker-Lewis Index=0.95, normed fit index=0.97, goodness-of-fit index=0.96, root mean square error of approximation=0.12, standardized root mean residual=0.03). Finally, the convergent validity analysis revealed a significant positive correlation with depression, anxiety, and anger, except for anger control, which is a sub-variable of anger. Conclusion The results showed that the Korean version of the BITe had good psychometric properties, and might serve as a valuable tool for assessing irritability in Korean patients with psychiatric disorders.