Comorbidity and Management of Concurrent Psychiatric and Medical Disorders.

Aging increases susceptibility to medical and psychiatric comorbidity via interrelated biological, psychological, and social mechanisms. Mental status changes or other psychiatric symptoms occurring in older adults with medical disorders most often result from delirium, depression, or the onset of Alzheimer's disease and related dementias (ADRD). Clinicians can use evidence-based tools to evaluate such symptoms including the 4A's Test for delirium, the Saint Louis University Mental Status Exam, and the Geriatric Depression Scale. Innovative models such as collaborative care can improve the outcome of care of older adults with medical disorders requiring treatment for depression or ADRD..