Dissociative and Somatoform Disorders 339
Understanding Dissociative Fugue
In the following sections we describe the research fi ndings related to dissociative
fugue, focusing on the possible role of the frontal lobes, the relationship between
the disorder and hypnotizability, and the role of traumatic events.
Neurological Factors
The fi ndings from several studies suggest that frontal lobe problems may underlie
dissociative fugue. In one study, Markowitsch and colleagues (1997) asked a patient
with dissociative fugue and normal controls to recall aspects of their lives while their
brains were being scanned. The patient’s brain was not as strongly activated in the
frontal and temporal regions as the control participants’ brains were. Moreover,
the right hemisphere was strongly activated in the control participants, but not
in the patient. The right hemisphere is known to play a special role in the retrieval
of autobiographical memories (Costello et al., 1998).
In another study (Glisky et al., 2004), researchers described a patient who lostnot only his memory about his past but also his memory of German, which was his
native language. This patient performed poorly on neuropsychological tests that assess
frontal lobe function (such as the ability to organize behavior and inhibit responses).
Moreover, as fMRI scans revealed, the frontal and parietal lobes of this patient were
not as strongly activated as those of normal control participants when he judged
whether letters formed words. The low activation in this patient’s frontal lobes was
particularly striking when he was asked to evaluate German words, which he claimed
he could not do. In sharp contrast, when normal bilingual participants (who spoke
German) were asked to pretend that they did not speak German when evaluating these
words, they exhibited large amounts of activation in the frontal lobes—which shows
that they worked hard to suppress their knowledge. Apparently, the patient wasn’t
simply pretending to have forgotten German, but actually had lost his memory.
The reduced activation in the frontal lobes of patients with dissociative fuguemight be a result of high levels of stress-related hormones (Markowitsch, 1999),
which could selectively affect processes that are involved in coordinating voluntary
actions and mental events—including memory retrieval (Kopelman, 2002).
Psychological Factors: Related to Hypnotizability?
People who have had dissociative fugue are often more hypnotizable than the
general population and may have a greater ability to dissociate (American Psychiatric
Association, 2000). There are three possible implications of this relationship:
- being more hypnotizable makes people more vulnerable to dissociative fugue
after experiencing stress; - having experienced a fugue state, people became more hypnotizable and pos-
sibly more able to dissociate; or - dissociative fugue and hypnotizability are not directly related to each other;
they are correlated, but their relationship is due to a third, unknown variable
(for example, and purely hypothetically, a neurological condition that affects
the frontal lobe).
Researchers have yet to begin to sort out the nature of this relationship, which is
especially challenging because so few cases of the disorder are available to study.
Social Factors: Combat Stress
Dissociative fugue generally occurs in response to signifi cant stressors that involve
social factors, such as combat (American Psychiatric Association, 2000). That is,
someone experiencing a dissociative fugue probably experienced a traumatic event
beforehand. As with dissociative amnesia, the specifi c mechanism by which the
traumatic event induces the fugue state is not clear.
To determine whether dissociative fugue is a phenomenon limited to Westerncultures, one team of researchers attempted to discover whether the DSM-IV-TR
defi nition of dissociative fugue applied to people in Uganda; in fact, it did not (van
Dujil, Cardena, & de Jong, 2005). However, some symptoms of dissociative fugue