depersonalization disorder

**Definition (DSM-5-TR):** Persistent or recurrent depersonalization (experiences of unreality, detachment, or being an outside observer of one's thoughts, feelings, body, or actions), derealization (world feels unreal, dreamlike, foggy, distant, or visually distorted), or both. Key requirement: **reality testing remains intact** (the patient knows the experience is a subjective feeling, not real). Causes clinically significant distress/impairment and is not attributable to substances (e.g., cannabis, hallucinogens, ketamine), a medical/neurologic condition (e.g., temporal lobe epilepsy, migraine), or better explained by another mental disorder (schizophrenia, panic disorder, PTSD, major depression, acute stress disorder).

**Epidemiology/Risk factors:** Lifetime prevalence ~1-2%; transient episodes are common in the general population (up to ~50% after life-threatening events). Typical onset in adolescence or early adulthood; rare after age 40. Equal sex distribution. Risk factors: childhood interpersonal trauma (especially emotional abuse/neglect), severe stress, anxiety/depression, and drug use (cannabis, hallucinogens, MDMA, ketamine can trigger it).

**Pathophysiology (proposed):** Hyperactivation of prefrontal inhibitory regions (e.g., ventrolateral prefrontal cortex) with dampened limbic/amygdala and insular responses, leading to emotional "numbing" and blunted autonomic response to emotional stimuli. HPA axis dysregulation is also implicated. It's thought of as a maladaptive extension of a protective response to overwhelming stress/threat.

**Clinical features:** Emotional or physical numbness, feeling like a robot or watching oneself in a movie, a sense of body parts being distorted, time distortion. Often coexists with anxiety and depression. Patients fear "going crazy," but there are no delusions or hallucinations.

**Differential diagnosis:** Psychosis (loss of reality testing), panic disorder (depersonalization during attacks only), PTSD (dissociative subtype), substance intoxication/withdrawal, seizure disorder, migraine aura, dissociative identity disorder (identity fragmentation, amnesia), and other dissociative disorders.

**Management:** Psychotherapy is first-line (CBT, grounding techniques, trauma-focused therapy). Treat comorbid anxiety/depression (SSRIs may help comorbid symptoms). No FDA-approved drug; evidence for lamotrigine, naltrexone, or SSRIs is limited/inconsistent. Benzodiazepines are generally not helpful. Avoid precipitating substances.

**Board pearls:** (1) Intact reality testing distinguishes it from psychosis. (2) Depersonalization = detached from self; derealization = detached from environment. (3) Dissociative amnesia = inability to recall important personal information; dissociative identity disorder = ≥2 distinct personality states. (4) Commonly triggered by trauma or cannabis use. (5) Must exclude substance/medical causes first.