DSM-5 Case Studies Practice Test

The key idea is depersonalization and/or derealization as the primary, ongoing problem. Depersonalization is a sense of detachment from oneself, as if watching oneself from outside, while derealization is a sense of unreality of the external world. In Depersonalization/Derealization Disorder, these experiences are persistent or recurrent, cause clinically significant distress or impairment, and reality testing remains intact (the person does not lose touch with what is real). Critically, the symptoms aren’t better explained by another disorder, a medical condition, or substance use. In the scenario, the patient’s persistent depersonalization or derealization is distressing and impairing, which aligns with this diagnosis. The other options focus on different mechanisms: PTSD and Acute Stress Disorder center on trauma-related symptoms (intrusions, avoidance, hyperarousal) rather than a primary, persistent detachment experience; Adjustment Disorder involves emotional/behavioral symptoms in response to a stressor but does not necessitate depersonalization/derealization as the core feature.