Commentary: dissociative amnesia and the future of forensic psychiatric assessment.

In their article, Pyszora et al. present the results of research in which they re-examined 50 violent offenders from an original case study. In the earlier study, they evaluated 59 amnesic violent offenders who received a life sentence in 1994 in England and Wales and compared them against a group of nonamnesic offenders (n 148). In the current follow-up study, the authors reinterviewed 31 of the original 59 violent offenders and applied neuropsychological and psychological measures, as noted within the body of their research report. Amnesia is the generic term for a severe nondissociative memory deficit, regardless of cause. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) gives four clinical characteristics that are typical of most amnesic patients: anterograde amnesia, retrograde amnesia, confabulation, and intact intellectual function. Anterograde amnesia is the hallmark of an amnestic disorder and refers to the inability, after the onset of the disorder, to acquire new information for explicit retrieval. Retrograde amnesia refers to difficulty in retrieving events that occurred before the onset of the amnestic disorder, often demarcated at the time of onset by head trauma, stroke, or other injury. Retrograde amnesia is more variably present in different amnesias. Confabulation does not occur in all amnesias, and it is often present only in the acute stage. Finally, in the classic amnestic disorders, the patient’s intellectual function remains relatively intact, even though some specific secondary cognitive defects may be noted on careful neuropsychological testing. Dissociative amnesia, on the other hand, as discussed in DSM-5 describes an inability to recall important autobiographical information (incidental memory), usually of a traumatic or stressful nature, which is inconsistent with ordinary forgetting. It often consists of localized or selective amnesia for a specific event or events. The symptoms cause clinically significant distress or impairment in other important areas of functioning. The disturbance is not attributable to physiological effects of a substance, a neurological or other medical condition, or other neurological disease. The disturbance is not better explained by dissociative identity disorder, posttraumatic stress disorder, acute stress disorder, somatic symptom disorder, or major or mild neurocognitive disorder. No methods for measurement or laboratory verification of putative dissociative amnesia are offered in DSM-5. Jean-Martin Charcot and Pierre Janet are the French neurologists most responsible for providing the beginning theories of dissociation. In the era of these two physicians, dissociative disorders were studied in great depth and detail, but after 1890, they received minimal attention for nearly 80 years. In the late 1980s and into the 1990s, there was a renaissance of interest. However, virtually no funds were made available for their systematic investigation. Virtually all of the literature with regard to dissociative disorders was based on using multiple personality disorder nomenclature. Controlled studies about the basic phenomena of the dissociative disorders were relatively few until the 1990s. The original theories of Janet were the first to show systematically a direct psychological defense against overwhelming trauDr. Granacher is Clinical Professor of Psychiatry, University of Kentucky College of Medicine, Lexington, KY. Address correspondence to: Robert P. Granacher, Jr, MD, MBA, 1401 Harrodsburg Road, Suite A400, Lexington, KY 40504. E-mail: [email protected].