Somatic symptom disorder

Somatic symptom disorder (SSD) is defined in the DSM-5 by the combination of at least one distressing physical symptom and a disproportionate psychological response to it — persistent thoughts about the symptom's seriousness, high health anxiety, or excessive time and energy devoted to it — with the symptom-focused state typically persisting for more than six months.

A key point is that the physical symptoms may or may not have an identifiable medical explanation; the diagnosis rests on the excessive response, not on whether the symptom is "medically unexplained." Patients genuinely experience their symptoms — they are not feigning — and often accumulate repeated medical visits, tests, and specialist referrals without reassurance.

SSD sits within a family of related diagnoses that exams love to contrast. Illness anxiety disorder features preoccupation with having a serious disease despite minimal or no somatic symptoms. Conversion disorder (functional neurological symptom disorder) presents with neurological deficits, such as paralysis or blindness, incompatible with recognized disease. Factitious disorder involves intentionally producing symptoms to assume the sick role, while malingering (not a mental disorder) involves faking symptoms for external gain such as money or avoiding work. A recognized management principle is regularly scheduled visits with a single primary provider to limit unnecessary testing.

USMLE Step 1 behavioral science tests somatic symptom disorder chiefly through differential diagnosis — distinguishing SSD from illness anxiety disorder, conversion disorder, factitious disorder, and malingering based on symptom presence, intent, and motivation.