Amnesia, dissociative disorders and delirium Quiz: Ace Your Exams

A 32-year-old person is brought to the emergency department by emergency services for evaluation of disorganized behavior. According to EMS, the patient was randomly knocking on doors in the neighborhood looking for someone named “Neil.” A bystander became alarmed when they noted the patient becoming verbally aggressive towards a tenant. The patient is unable to state their name, date of birth, or place of residence. The patient does not recall any medical history or remember taking any medications daily. When asked what they were doing knocking on doors, the patient responds, “I just had to find Neil.” Vital signs are within normal limits. Physical examination reveals a muscular, young adult in no acute distress. The patient has several military dog tags around their neck. Their blood alcohol level is undetectable, and a urine drug screen is negative. The remainder of laboratory studies and a CT of the brain are within normal limits. Shortly thereafter, a police officer confirms the patient is a missing person and has been away from home for nearly a month after returning from combat overseas. Which of the following is the most likely diagnosis?