Derealisation

Derealisation is a dissociative symptom characterized by a persistent or recurrent sense that the external world is unreal, distant, or distorted. People may perceive objects as enlarged or diminished, feel a lack of vividness, or experience time that seems sped up or slowed. It is often accompanied by depersonalization, the sense of being detached from oneself, though it can occur on its own. When derealisation is brief and infrequent, it may occur in situations of extreme stress or fatigue. When episodes are persistent and cause distress or impairment, they may reflect derealization–depersonalization disorder.

Causes and triggers: It can occur in the context of anxiety, panic, trauma, sleep deprivation, or substance use or withdrawal (for example cannabis, hallucinogens, alcohol). It may be associated with medical conditions such as migraines, temporal lobe epilepsy, or other neurologic disorders. It can occur in mood and anxiety disorders, PTSD, or during acute stress.

Diagnosis: Based on clinical evaluation; there are no definitive laboratory tests for the symptom; clinicians assess duration, frequency, distress, and rule out medical or substance causes; DSM-5-TR criteria for derealization–depersonalization disorder can apply when symptoms are persistent and impair functioning; differential includes psychosis, delirium, seizures, migraines, and dissociative states.

Treatment and prognosis: The approach targets underlying causes and may include psychotherapy (cognitive-behavioral therapy, grounding techniques, and trauma-focused therapies), education about the symptom, sleep management, and stress reduction. Pharmacotherapy is not specific for the symptom; antidepressants or anxiolytics may help when there are comorbid conditions. Many people experience transient episodes that resolve on their own; for others, symptoms may persist and require ongoing management.