Clinical Vignette
Patient: "Mr. E," 48-year-old accountant, found by police 200 miles from his home with no identification, unable to state his name, address, or any personal information.
Chief Concern: Mr. E (name provided later by wife): "I don't know who I am. I don't know how I got here. I remember waking up on a park bench but nothing before that. I can't remember my name, my family, or where I live."
History of Present Illness: Mr. E was found disoriented on a park bench 200 miles from his home by local police. He could not state his name, age, address, occupation, or any autobiographical information. He was alert, oriented to the present situation (knew he was talking to police, knew it was morning, knew the city he was in), and his procedural memory was intact (could drive, use a phone, read, perform arithmetic). He had no identification. His wife filed a missing person report 3 days after he failed to return from work. Police matched him through a surveillance camera at a gas station midway between his home and where he was found, where he appeared to be functioning (purchased gas, paid with cash). His wife reports that he left for work on a Monday morning during the period of the company's annual audit — which Mr. E had been dreading for months, describing it as 'the most stressful week of my career' and expressing fear that 'irregularities in the books' would be discovered (he was not responsible for the irregularities but feared being blamed). MRI brain: normal. EEG: normal. Toxicology: negative. After 48 hours of supportive care and gentle questioning, his autobiographical memory began returning in fragments.
Medical History: No neurological conditions. No head injury. No epilepsy.
Mental Status Exam: Alert, cooperative, distressed about memory loss. Speech normal. Oriented to place, time, situation but NOT to personal identity. Procedural knowledge intact (demonstrated literacy, numeracy, appropriate social behavior). Semantic knowledge intact (general knowledge of world events, current president). Autobiographical/episodic memory: absent (cannot recall personal details). No confabulation. No psychotic symptoms.
Step 1: Dissociative Amnesia DSM-5-TR Criteria
Criterion A: An inability to recall important autobiographical information, usually of a traumatic or stressful nature, that is inconsistent with ordinary forgetting.
Complete loss of autobiographical memory (name, family, address, occupation, personal history). This is NOT ordinary forgetting. Selective: procedural and semantic memory preserved while episodic/autobiographical memory is lost. MET — GENERALIZED DISSOCIATIVE AMNESIA.
Criterion B: Symptoms cause clinically significant distress or impairment.
Found by police, unable to identify himself. Unable to return home or contact family. Significant distress about identity loss. MET.
Criterion C: Not attributable to substance or neurological/medical condition.
Toxicology negative. MRI brain normal. EEG normal. No head injury. No seizure activity. MET.
Criterion D: Not better explained by DID, PTSD, acute stress, somatic symptom, or neurocognitive disorder.
No identity alternation (excludes DID). No trauma criterion for PTSD/ASD. Memory loss is the primary and sole symptom. MET.
Specifier: With Dissociative Fugue
Apparently purposeful travel (drove 200 miles, purchased gas, navigated). Travel occurred during the amnesia period. Meets fugue specifier criteria. WITH DISSOCIATIVE FUGUE.
Step 2: Neurological vs. Dissociative Amnesia
| Feature | Dissociative Amnesia | Neurological Amnesia (TGA, stroke) | This Patient |
|---|---|---|---|
| Memory type affected | Autobiographical/personal | Recent/anterograde | Dissociative: autobiographical only |
| Procedural memory | Preserved | Usually preserved | Preserved |
| Semantic memory | Preserved | Variable | Preserved |
| Can form new memories? | Yes (anterograde memory intact) | Often impaired (TGA) | Yes — remembers events after being found |
| Onset context | Psychological stressor | Vascular or neurological event | Dissociative: preceded by severe work stress |
| Neuroimaging/EEG | Normal | Often abnormal | Normal MRI and EEG |
| Recovery pattern | Gradual return in fragments | Gradual anterograde recovery | Fragmentary return over 48 hours |
The Dissociative Memory Pattern
The selective loss of autobiographical memory with preservation of procedural and semantic memory, normal neuroimaging, psychological precipitant (impending audit), and purposeful travel during the amnestic period are diagnostic of Dissociative Amnesia with fugue. Neurological amnesia (TGA, stroke) would impair anterograde memory formation and would be detectable on imaging.
Diagnostic Formulation
Diagnostic Conclusion
Dissociative Amnesia, with Dissociative Fugue (F44.1): All 4 DSM-5-TR criteria met. Generalized dissociative amnesia (loss of all autobiographical information). Dissociative fugue specifier (purposeful travel of 200 miles during amnestic period). Clear psychological precipitant (dreaded work audit). Neurological etiologies excluded (normal MRI, EEG, toxicology). Treatment: supportive care during acute episode (memory typically returns spontaneously), CBT for stress management, address underlying occupational stressors.
Teaching Points
- Dissociative Amnesia is characterized by the loss of autobiographical memory with preservation of procedural and semantic memory. This pattern is the opposite of most neurological amnesias, which impair recent/anterograde memory while preserving distant/autobiographical memories. The selective nature is diagnostically useful.
- The dissociative fugue specifier applies when apparently purposeful travel or bewildered wandering occurs during the amnestic episode. Mr. E drove 200 miles and purchased gas — actions requiring intact procedural skills, navigation, and executive function — all while having no autobiographical memory.
- DSM-5-TR distinguishes three patterns of dissociative amnesia: localized (specific time period), selective (partial events during a period), and generalized (complete loss of life history). Mr. E's presentation is generalized, which is the most dramatic and least common form.
- Psychological precipitants are typically identifiable in dissociative amnesia, though not always at initial presentation. Mr. E's amnesia began in the context of a dreaded annual audit with feared personal consequences. The amnesia functioned (not consciously) to remove him from the threatening situation.
- Recovery from dissociative amnesia is typically spontaneous, occurring over hours to days in a supportive environment. Hypnosis and amobarbital interviews, while historically used, have limited evidence and carry the risk of producing false memories. Supportive care with gentle, non-pressured questioning is the preferred approach.