A patient is brought in by a social worker after a recent earthquake. He has been living in a town different from his place of origin and is unaware of how he traveled 110 km away from home. He cannot recall his identity. There’s no substance abuse history. What is the most likely diagnosis?

Explanation

## Correct Answer: D. Dissociative fugue Dissociative fugue is characterized by sudden, unexpected travel away from home or workplace with inability to recall one's past identity, combined with confusion about personal identity or assumption of a new identity. The key discriminating features in this case are: (1) **purposeful travel** 110 km away from home, (2) **loss of personal identity awareness**, (3) **no recall of how he traveled**, and (4) **precipitating stressor** (earthquake—a severe psychological trauma). The patient is not in a dissociative state at the time of presentation but has recovered enough to be brought in by a social worker, suggesting the fugue episode may be resolving. Unlike dissociative amnesia (which is localized memory loss without travel), fugue involves organized, goal-directed behavior during the dissociative episode. The absence of substance abuse history rules out organic causes. In Indian clinical practice, fugue states are often seen post-disaster (earthquakes, floods, communal violence) and represent a severe dissociative response to overwhelming trauma. The patient's ability to function and travel despite amnesia distinguishes this from other dissociative disorders. Recovery is typically complete once the fugue state ends, though the amnestic gap for the fugue period itself persists. ## Why the other options are wrong **A. Dissociative amnesia** — Dissociative amnesia involves **localized memory loss** (typically for a specific traumatic event or period) without purposeful travel or identity confusion. The patient would remain in his original location and retain awareness of who he is. The 110 km travel and loss of personal identity are hallmark features of fugue, not simple amnesia. This is the NBE trap—students confuse amnesia as the core feature of all dissociative disorders. **B. DID** — Dissociative Identity Disorder requires **multiple distinct personality states** that recurrently take control of behavior, with evidence of switching between identities. This patient shows no evidence of alternate personalities or switching behavior—only a single fugue episode with identity loss. DID typically has a chronic course with childhood trauma history; fugue is acute and post-disaster. The absence of co-consciousness or identity switching rules out DID. **C. Selective amnesia** — Selective amnesia is **not a recognized DSM-5 dissociative disorder diagnosis**. It is sometimes used colloquially to describe partial memory loss for specific events, but it lacks the organized travel component and identity confusion seen here. This is a distractor term that tests whether students know the formal diagnostic nomenclature. The structured travel and identity loss point to fugue, not selective forgetting. ## High-Yield Facts - **Dissociative fugue** = purposeful travel + identity loss + inability to recall past, triggered by severe stress (earthquake, violence, war). - **Key discriminator from amnesia**: fugue involves *organized travel behavior* and *identity confusion*; amnesia is localized memory loss without travel. - **Post-disaster fugue** is common in Indian populations after earthquakes, floods, and communal violence; recovery is usually complete once fugue resolves. - **Duration**: fugue episodes typically last hours to days; longer episodes may indicate other dissociative or organic pathology. - **No substance abuse** rules out alcohol blackout or drug-induced dissociation; fugue is purely psychological. - **DSM-5 criterion**: fugue requires sudden, unexpected travel *and* confusion about identity or assumption of new identity—both present here. ## Mnemonics **FUGUE = F.U.G.U.E** **F**ar travel (purposeful, unexpected) | **U**nable to recall identity | **G**enerally triggered by stress | **U**sually resolves completely | **E**pisodic (acute onset, not chronic) **Fugue vs. Amnesia: Travel Test** If patient **traveled far away** → Fugue. If patient **stayed put** → Amnesia. Fugue = Fugit (Latin: to flee). Use this when differentiating dissociative disorders in trauma cases. ## NBE Trap NBE pairs "amnesia" with "dissociative disorder" to lure students into choosing dissociative amnesia. The trap is that amnesia is present in both amnesia and fugue, but only fugue involves purposeful travel and identity confusion. Students must recognize that travel + identity loss = fugue, not simple amnesia. ## Clinical Pearl In Indian disaster medicine, fugue states are frequently encountered post-earthquake or post-communal violence. The patient often appears functional and may travel considerable distances, making identification difficult. Social workers and NGOs frequently encounter such cases in relief camps. Recognition is critical because these patients typically recover completely once the acute dissociative state resolves, and reassurance plus supportive care (not antipsychotics) is the mainstay of management. _Reference: DSM-5 (Dissociative Disorders section); Harrison's Principles of Internal Medicine Ch. 387 (Psychiatric Disorders); Kaplan & Sadock's Synopsis of Psychiatry (Dissociative Disorders)_