Delirium in the elderly.

Delirium is an organic psychiatric syndrome characterized by acute onset and impairment in cognition, perception, and behavior. The most common and serious mental disorder in old age, delirium heralds death in about 25% of afflicted elderly patients. Despite this high mortality rate, it is usually a transient disorder, resulting in full recovery without progressing to a chronic mental disorder. Almost any physical illness may cause delirium in an elderly person. Prompt assessment, differential diagnosis, and treatment are essential to reverse the medical disorder and control behavior that may be life threatening. This paper presents an approach to the diagnosis of delirium, reviewing descriptive features of the syndrome, biological, psychological, and environmental variables predisposing to delirium in geriatric patients, and the most common medical etiologies. It describes effective therapeutics, including ward management, supportive psychotherapy, and pharmacotherapy.