Hughlings Jackson and Dissociation

To the Editor: Russell Meares, M.D., is to be lauded for resurrecting the rich model of the mind mapped out by neurologist John Hughlings Jackson a century ago (1). However, his review of recent dissociation research suffers from significant lacunae. In point of fact, by suggesting that Jackson’s overlooked contribution can cure what now ails the field, Dr. Meares created a compelling but misleading narrative.

Curiously, Dr. Meares cited studies from the 1960s and 1970s in support of his belief that today’s investigators use the term “dissociation” too loosely. He thus neglected to mention new tools and the wealth of recent scientific investigations that have refined our understanding of dissociation (2). For example, clinicians now routinely use both the Dissociative Experiences Scale (3) to screen for symptoms and the Structured Clinical Interview for DSM-IV Dissociative Disorders (4, 5) to evaluate the severity of specific dissociative symptoms and to diagnose dissociative disorders. Furthermore, because of these reliable and valid measures, researchers have been able to document the precise nature of dissociative symptoms in hundreds of publications (6–11).

In the final analysis, although Jackson’s work is of historical interest as we continue to reformulate the mind/brain nexus, scientific advances in the past two decades have already rendered dissociation considerably less elusive.