ICD-11 Definition of Dissociation
ICD-11 does not provide a standalone definition of dissociation as a general concept; instead, it addresses dissociative phenomena within specific diagnostic contexts, most notably as a symptom feature in Borderline Personality Disorder and as a defining characteristic of Complex PTSD.
Dissociation in ICD-11 Personality Disorders
ICD-11 identifies dissociative symptoms as one of the clinical features that may appear in Borderline Personality Disorder, alongside impulsivity, unstable mood and interpersonal relationships, and self-damaging behaviors 1.
The ICD-11 personality disorder framework allows specification of maladaptive personality traits including negative affectivity, detachment, dissociality, disinhibition, anankastia, and borderline pattern, with dissociative symptoms forming part of the borderline pattern presentation 1.
Dissociation in ICD-11 Complex PTSD
Within the Complex PTSD diagnosis, ICD-11 recognizes dissociative phenomena as part of the broader constellation of symptoms that includes severe disturbances in affect regulation, negative self-concept, and difficulties sustaining relationships 2.
Complex PTSD in ICD-11 typically follows prolonged or repeated traumatic exposures such as childhood abuse, domestic violence, or torture, contexts in which dissociative symptoms are particularly common 2.
Contrast with DSM-5 Definition
While ICD-11 embeds dissociative phenomena within specific disorder criteria, DSM-5 provides an explicit general definition: dissociation is a "disruption of the usually integrated functions of consciousness, memory, identity or perception of the environment" 3.
DSM-5 recognizes dissociation across multiple psychiatric disorders including primary dissociative disorders, PTSD, depression, and panic disorder, as well as in medical conditions such as epilepsy and traumatic brain injury 3.
Clinical Manifestations Across Diagnostic Systems
Dissociative phenomena encompass derealization, depersonalization, distortions of perception of time, space, and body, and conversion symptoms 4.
In epilepsy, ictal dissociative-like experiences include déjà vu/jamais vu, depersonalization, derealization, autoscopy, and out-of-body experiences, particularly in focal seizures of temporal lobe origin involving the amygdala and hippocampus 3.
Cognitive and Neurophysiological Mechanisms
Dissociation is characterized by subtle neuropsychological deficits including heightened distractibility, weakened cognitive inhibition in emotional or attentional contexts, and an enhanced propensity toward pseudo-memories mediated by interrogative suggestibility and fantasy proneness 5.
Neurophysiological studies in nonclinical populations show that individuals scoring high in dissociation with inconsistent handedness display left hemispheric lateralization across frontal, central, and parietal regions 6.
Two distinct categories of dissociative phenomena have been proposed: "detachment" (alterations in subjective experience) and "compartmentalization" (lack of integration of mental processes), which have different psychological mechanisms and treatment implications 7.
Common Pitfalls in Clinical Assessment
Do not assume dissociation is always pathological; dissociative experiences exist on a continuum and may occur in nonclinical populations, during sleep deprivation, substance intoxication, or as normal responses to extreme stress 3, 4.
Avoid relying solely on self-report measures when assessing dissociation in personality disorders, as patients often have impaired insight; structured interviews and collateral information from multiple sources are essential 1.
Distinguish dissociative symptoms from overlapping presentations such as psychomotor retardation in depression, delirium, or factitious disorder by carefully evaluating the temporal relationship to trauma, the presence of other PTSD symptoms, and the pattern of symptom fluctuation 2.