Patients should consult a physician if they experience significant and unexplained memory loss. Sudden changes in behavior in the face of stress also may warrant a visit to a healthcare professional. Finally, a chronic feeling that the world is somehow "unreal" may indicate the presence of a dissociative disorder that requires treatment.

Early intervention can be an important factor in the eventual success of treating dissociative disorders. For this reason, individuals should seek medical attention and counseling after abuse or other significant trauma. Parents or caregivers should seek intervention for any child that has suffered physical or emotional trauma.

Before diagnosing a dissociative disorder, a physician will review the patient's medical history and should perform a physical examination and blood tests. These steps will be used to rule out other potential sources of symptoms, such as head injuries, brain diseases, sleep deprivation, substance abuse or intoxication.

If a physician suspects a dissociative disorder, the patient may be referred to a psychiatrist, psychologist or other mental health professional for further evaluation and treatment. During the interview, mental health professionals will ask questions about significant childhood and adult trauma, and check for symptoms of dissociative experiences.

Techniques such as hypnosis to help identify alternate personalities or repressed memories associated with dissociative disorders should be considered only in consultation with the patient after safety has been established and skills to deal with traumatic memories have been taught to the patient.

In attempting to diagnose a dissociative disorder, a physician may ask questions of patients, such as:

• Do they have problems remembering things?
  
  
• Have they ever found themselves traveling away from home unexpectedly?
  
  
• Do they ever feel as if someone else is controlling their behavior?
  
  
• Do they ever feel detached from themselves or their surroundings?

All dissociative disorders have their own diagnostic criteria as defined by the American Psychiatric Association. There are criteria for each of the four major dissociative disorders.

Dissociative amnesia:

• Predominant disturbance involves one or more episodes of inability to recall personal information, typically of a traumatic or stressful nature. The memory lapse must be too extensive to be attributed to normal forgetfulness.
  
  
• Episodes do not occur exclusively during dissociative identity disorder, dissociative fugue, post-traumatic stress disorder, acute stress disorder or somatization disorder.
  
  
• Symptoms cause significant distress or impairment in social, occupation or other areas of functioning.

Dissociative fugue:

• Predominant disturbance is sudden unexpected travel away from home or place of work accompanied by inability to remember the past.
  
  
• Patient has confusion about personal identity or assumes a new identity.
  
  
• Episodes do not occur exclusively during dissociative identity disorder.
  
  
• Symptoms cause significant distress or impairment in social, occupation or other areas of functioning.

Dissociative identity disorder:

• Marked by the presence of two or more distinct personalities, each of which has its own pattern of perceiving, relating to or thinking about the environment or self.
  
  
• At least two identities recurrently take control of a patient's behavior.
  
  
• Inability to recall personal information is too extensive to be attributed to normal forgetfulness.

Depersonalization disorder:

• Marked by persistent or recurrent feelings of being detached from one's mental processes or body.
  
  
• During feelings of depersonalization, reality testing remains intact, meaning the patient is aware that the depersonalization is just a feeling.
  
  
• Depersonalization causes significant distress or impairment of social, occupational or other areas of functioning.
  
  
• Depersonalization does not occur exclusively during the course of another mental disorder, such as schizophrenia, panic disorder, acute stress disorder or another dissociative disorder.

In addition, none of these disorders can be due to another general medical condition or the direct physiological effects of a substance.

Symptoms of dissociation are also included in the diagnostic criteria of several other mental disorders. Thus, patients whose symptoms do not meet the criteria for the four major dissociative disorders may still be diagnosed with another mental disorder, such as acute stress disorder, post-traumatic stress disorder or somatization disorder. Patients whose dissociative symptoms appear exclusively during the course of these disorders will not be diagnosed with a dissociative disorder.

In addition, dissociative disorders are not diagnosed in people whose dissociative symptoms are related to accepted cultural or religious activities in their society. In such cases, no disorder is considered present unless it leads to significant distress or impairment. Dissociative disorders can be extremely difficult to diagnose. Research indicates that patients receive mental health treatment for up to eight years before they receive a diagnosis of a dissociative disorder.