When an individual exhibits two completely opposite personalities or identities within themselves, it is often referred to as "dissociative identity disorder" (DID), formerly known as multiple personality disorder. DID is a complex and rare psychological condition characterized by the presence of two or more distinct personality states or identities, also known as alters.
These distinct identities may have their unique ways of thinking, behaving, and perceiving the world. They can manifest as different ages, genders, names, and may have contrasting memories and experiences. The transition from one identity to another is typically accompanied by memory gaps and may happen involuntarily.
It's essential to note that DID is a complex and controversial diagnosis, and individuals with the condition often require specialized professional help and support to cope with their experiences and integrate their various identities. The understanding and treatment of DID have evolved over the years, and it remains a subject of ongoing research and study in the field of psychology and psychiatry.