Organic brain syndrome. The psychiatric imposter.

Rapid differentiation of organic brain syndrome (OBS) from functional psychiatric illness can be difficult when patients come to an emergency department with predominantly psychiatric symptoms. Using four screening criteria-disorientation, abnormal vital signs, clouded consciousness, and patients older than 40 years with no previous psychiatric history-we detected 38 cases of OBS from 1,140 medically cleared patients. Twelve of these patients were subsequently admitted to a medical unit. Despite the presence of striking behavioral aberration, an increased awareness of the clinical manifestations of OBS will enhance the physician's ability to discriminate OBS from other psychiatric illness.