“…tt is now well recognized that delusions and hallucinations occurring in late life can be the manifestations of many different medical or psychiatric illnesses, leading to diagnoses of dementia, delirium, or another organic mental disorder, mood disorder, schizophrenia, or delusional disorder (Stoudemire and Riether, 1987). Less than one century ago, psychoses in old age were considered 'the darkest area of psychiatry' (Emil Kraepelin, cited in Pearlson and Rabins, 1988); late onset psychoses were invariably attributed to either arteriosclerosis or senility (ie central nervous system (CNS) degeneration), even in the presence of associated features such as clouding of consciousness or prominent mood symptoms (Roth, 1955).…”