Multiple personality disorder (MPD), now known as dissociative identity disorder (DID), is an officially recognized mental disorder and has been included in the international diagnostic manuals (DSM and ICD). The major features of DID include (1) the presence of at least two distinct identities or personality states that recurrently take control of the individual's behaviour (e.g., switching from one alternate personality states to another) and (2) psychological amnesia (e.g., memory gaps, inability to remember personal information or traumatic events). In some cultures, the symptoms of DID may be described as an experience of possession. Many persons who live with DID also suffer from other psychiatric symptoms, such as depression, auditory hallucinations and other posttraumatic symptoms (Ross, 1997). Some scholars believe that DID is a socially constructed phenomenon rather than a trauma disorder, while some other researchers provide evidence of DID’s validity and its relationship with trauma (Brand et al., 2016). Epidemiological studies suggest that about 1% of the general population may have DID; in psychiatric settings, DID is even more common (Şar, 2011). However, patients with DID usually have been in the health and social service systems and treated as having other conditions (e.g., depression, psychosis/schizophrenia) for many years before they are correctly diagnosed and appropriately treated. DID is highly associated with childhood trauma, such as physical abuse, emotional abuse, emotional neglect and family violence. DID is generally understood as the most severe form of posttraumatic psychopathology, and a cross-culturally occurring trauma disorder. Patients with DID usually respond well to specialized psychotherapy. In fact, DID is a creative and adaptive strategy for surviving complex trauma, allowing the victim to continue to manage daily life (e.g., learn in class, socially engage with friends) despite having overwhelming experiences.