Contents
Introduction
Defined by feeling detached from the own feelings and/or experiences (depersonalization, DP) and/or experiencing objects, people, and/or surroundings as unreal, distant, artificial, and lifeless (derealization, DR) while reality testing remains intact.
WHO . The ICD-10 classification of mental and behavioural disorders: Diagnostic criteria for research. Geneva: World Health Organization; 1993
- Classified under dissociative disorders.
Dissociative disorders:
Dissociation often begins in childhood and can occur in adult life as a normal adaptive measure when danger or trauma is encountered; the dissociated state presumably enables the individual to tolerate the circumstances. Dissociation becomes pathological when the individual is unable to control when and where it occurs or when the adaptive measure becomes generalized to other situations and circumstances, or when it persists beyond the presence of danger.
- Dissociative amnesia
- Dissociative fugue
- Dissociative identity disorder
- Depersonalization-derealization syndrome (DDS)
- Dissociative disorder not otherwise specified
Aetiology
Immediate precipitants:
- Severe stress
- Depression
- Panic
- Marijuana and hallucinogen ingestion
Long-term factors:
- Childhood interpersonal trauma (esp. emotional maltreatment)
Clinical features
- Depersonalization: Sensation of being detached from one’s body, often associated with feelings of loss of control over one’s own body, actions, or thoughts
- Derealization: Altered perception of one’s surroundings that is experienced as unreal

Brain imaging studies:
- Widespread alterations in metabolic activity in the sensory association cortex, as well as prefrontal hyperactivation and limbic inhibition in response to aversive stimuli.
- Depersonalisation disorder has also been associated with autonomic blunting and hypothalamic-pituitary-adrenal axis dysregulation.
Epileptogenic zone in patients with ictal depersonalization‐like phenomena. Lesion overlap analysis highlighted the right medio‐dorsal premotor cortex (PMC) [cantered on Montreal Neurological Institute (MNI) x = 18, y = −5, z = 59, Brodmann area 6], which was found to be involved in in five out of nine patients with DP. The number of overlapping lesions is illustrated by color, from violet (n = 3) to red (maximal lesion overlap, n = 5). | Heydrich, L., Marillier, G., Evans, N., Seeck, M., & Blanke, O. (2019). Depersonalization- and derealization-like phenomena of epileptic origin. Annals of clinical and translational neurology, 6(9), 1739–1747. https://doi.org/10.1002/acn3.50870 Epileptogenic zone in patients with ictal derealization‐like phenomena. Lesion overlap analysis highlighted the right posterior mesial temporal lobe (MTL) [centered on Montreal Neurological Institute (MNI) x = 28, y = −21, z = −14], which was found to be involved in four out of seven patients with DR. The number of overlapping lesions is illustrated by color, from violet (n = 2) to red (maximal lesion overlap, n = 4). Heydrich, L., Marillier, G., Evans, N., Seeck, M., & Blanke, O. (2019). Depersonalization- and derealization-like phenomena of epileptic origin. Annals of clinical and translational neurology, 6(9), 1739–1747. https://doi.org/10.1002/acn3.50870
Management
- Selective serotonin reuptake inhibitors (SSRI)
- Serotonin norepinephrine reuptake inhibitors (SNRI)
- Antipsychotics