Depersonalisation neurosis is a mental disorder that causes a feeling of detachment or distance from oneself and one's surroundings. It is also known as dissociative disorder, depersonalisation disorder, or self-alienation. The condition is characterised by symptoms such as feeling detached, unconnected, or like an outsider. Other synonyms for depersonalisation neurosis include derealisation disorder, identity disorder, dissociative fugue, and dissociative amnesia. These terms are used to describe the same condition, but may have different nuances or levels of severity. Regardless of the terminology used, treatment for depersonalisation neurosis typically involves psychotherapy, medication, or a combination of the two.