Diagnosis

Diagnosis usually involves assessment of symptoms and ruling out any medical condition that could cause the symptoms. Testing and diagnosis often involves a referral to a mental health professional to determine your diagnosis.

Evaluation may include:

• Physical exam. Your doctor examines you, asks in-depth questions, and reviews your symptoms and personal history. Certain tests may eliminate physical conditions — for example, head injury, certain brain diseases, sleep deprivation or intoxication — that can cause symptoms such as memory loss and a sense of unreality.
• Psychiatric exam. Your mental health professional asks questions about your thoughts, feelings, and behavior and discusses your symptoms. With your permission, information from family members or others may be helpful.
• Diagnostic criteria in the DSM-5. Your mental health professional may compare your symptoms to the criteria for diagnosis in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published by the American Psychiatric Association.

For diagnosis of dissociative disorders, the DSM-5 lists these criteria.

Dissociative amnesia

For dissociative amnesia:

• You've had one or more episodes in which you couldn't remember important personal information — usually something traumatic or stressful — or you can't remember your identity or life history. This memory loss is too extensive to be explained by ordinary forgetfulness.
• Your episodes of memory loss don't occur only during the course of another mental health disorder, such as post-traumatic stress disorder. Also, your symptoms are not due to alcohol or other drugs, and they're not caused by a neurological or other medical condition, such as amnesia related to head trauma.
• You may also experience dissociative fugue, where you purposefully travel or experience confused wandering that involves amnesia — inability to remember your identity or other important personal information.
• Your symptoms cause you significant stress or problems in your relationships, work or other important areas of your life.

Dissociative identity disorder

For dissociative identity disorder:

• You display, or others observe, two or more distinct identities or personalities, which may be described in some cultures as possession that is unwanted and involuntary. Each identity has its own pattern of perceiving, relating to and thinking about yourself and the world.
• You have recurrent gaps in memory for everyday events, skills, important personal information and traumatic events that are too extensive to be explained by ordinary forgetfulness.
• Your symptoms are not a part of broadly accepted cultural or religious practice.
• Your symptoms are not due to alcohol or other drugs, or a medical condition. In children, symptoms are not due to imaginary playmates or other fantasy play.
• Your symptoms cause you significant stress or problems in your relationships, work or other important areas of your life.

Depersonalization-derealization disorder

For depersonalization-derealization disorder:

• You have persistent or recurrent experiences of feeling detached from yourself, as if you're an outside observer of your thoughts, sensations, actions or your body (depersonalization). Or you feel detached or experience a lack of reality for your surroundings as if you're in a dream or the world is distorted (derealization).
• While you're experiencing an episode of depersonalization or derealization, you're aware the experience is not reality.
• Your symptoms do not occur only during the course of another mental disorder, such as schizophrenia or panic disorder, or during another dissociative disorder. Your symptoms are also not explained by the direct effects of alcohol or other drugs, or a medical condition, such as temporal lobe epilepsy.
• Your symptoms cause you significant stress or problems in your relationships, work or other important areas of your life.