Depersonalization: A New Look at a Neglected Syndrome

Depersonalization is a fascinating phenomenon that challenges assumptions regarding one's existence and identity. Depersonalization is an alteration in the perception or experience of the self, so that one feels detached from, or as an outside observer to one's mental processes or body, as if in a dream, or feeling unreal. In this scholarly book, Sierra pulls together recent research and relates it to 100 years of thinking about this puzzling condition. He also provides a scale in the appendix that serves as a very useful screening tool for depersonalization for clinicians and investigators.

While the book is subtitled A New Look at a Neglected Syndrome, I would suggest that there is quite a lot of interest in this syndrome at the current time. For example, the DSM-5 Work Group on Anxiety, Obsessive-Compulsive Spectrum, and Posttraumatic, and Dissociative Disorders is evaluating whether to group dissociative disorders such as depersonalization disorder within a broader grouping of posttraumatic and anxiety conditions.

The syndrome and its symptoms have been well described since the early 19th century, with extensive case series published in the 1940s and 1950s, and again in another burst of interest in the 1990s and 2000s. However, throughout the years, the clinical presentations have been surprisingly similar with regard to signs and symptoms. Depersonalization disorder is certainly not rare, having a prevalence of about 1% of the population. It begins in the teens, may last for decades, and is remarkably refractory to most treatments.

Depersonalization is described by Sierra as lying along a spectrum of severity, from sporadic and fleeting experiences in youth, which are quite common (up to 70% of college students and 23% of the general population), to symptoms accompanying other comorbid conditions (such as anxiety or obsessive-compulsive disorder), and finally to the severe and disabling pathological depersonalization disorder. Of interest, Daphne Simeon and others have shown that emotional abuse in childhood may predispose to both the nonclinical and pathological forms of depersonalization.

Drug-induced flashbacks and "bad trips" leading to depersonalization disorder have been reported to be precipitated by cannabis, LSD, MDMA (Ecstasy), and ketamine, and are vividly described in the book. These experiences provide clues to the role of terror and loss of control, as well as neurotransmitter mechanisms that play a role in the development of the disorder.

The neurology of the disorder and cultural factors are also well described in the book. Western cultures with their greater emphasis on individualism are surprisingly associated with greater frequency of depersonalization. Of course, pharmacological and psychological approaches to treatment are described, but it is truly remarkable how resistant this disorder remains.

Of greatest interest is Sierra's fronto-limbic, neurobiological model of depersonalization, which posits that depersonalization is a response to deal with extreme anxiety by combining a state of increased alertness with a profound inhibition of the emotional response system by the prefrontal cortex. The prefrontal cortex down-regulates emotional processing of the limbic system, resulting in dampened sympathetic output and reduced emotional experiencing. This response has evolved to cope with life-threatening situations in which the individual does not have control over the situation and the source of danger cannot be localized in space. Inhibition of nonfunctional emotional reactions and the fight-or-flight mechanism, along with increased scanning of survival-relevant information, would be helpful from an evolutionary perspective.

This book provides a wealth of data regarding depersonalization. It attempts with some success to pull together threads from over a century of writings and integrate these observations with recent neurobiological investigations in order to develop a unifying model of the syndrome. It should be an absorbing read not only for scholars working in this field, but also for clinicians who treat patients with depersonalization, as well as keen observers of the human condition.