Diagnosis

It is difficult to report reliable data on the prevalence of dissociative disorders,

but it appears that women are diagnosed with the dissociative disorders

at a rate five times that of men.

To make the diagnosis of dissociative amnesia, a doctor must identify a

disturbance in memory that involves the appearance of one or more episodes

of inability to recall important personal information that is usually of a

traumatic or stressful nature. The memory loss must be too extensive to be

explained by ordinary forgetfulness. When people develop dissociative amnesia,

they may not be able to remember their own names or the identities

of relatives, but they retain a number of significant abilities. In psychogenic

or dissociative amnesia, basic habits and skills remain intact. Thus, the person

is still able to read a book, drive a car, and recognize familiar objects.

The memories that are lost revolve around life events and autobiographical

information.

The diagnosis of dissociative fugue requires sudden, unexpected travel

away from the home or customary place of work. Together with this travel,

the person is unable to recall the past. During the fugue, the person shows

confusion about personal identity or assumes a new one. The person’s activities

at the time of the fugue can vary extensively, from short-term involvement

in new interests to traveling to distant locations and assuming a new

identity and work roles. The fugue can last for days, weeks, or even years. At

some point, the individual will leave the fugue state and be in a strange place

without awareness of the events that took place during the dissociative period.

When a fugue state is taking place, the person appears normal to others

and can complete complex tasks. Usually, the activities selected by the

person are indicative of a different lifestyle from the previous one.

The diagnosis of dissociative amnesia and fugue can be controversial because

it often depends upon self-reports. The possibility that a person is fak

ing the symptoms must be considered. Objective diagnostic measures for

these disorders do not exist. The possibility of malingering or fabricating

the symptoms must be considered in arriving at a diagnosis of dissociative

amnesia and fugue.

When diagnosing dissociative amnesia and fugue, a number of other disorders

and conditions have to be excluded. A number of medical conditions

such as vitamin deficiency, head trauma, carbon monoxide poisoning, and

herpes encephalitis can produce similar symptoms. Amnesia can also be

found in conjunction with alcoholism and the use of other drugs.