Dementia in the aged.

Dementia can be feature of several distinct pathologic processes, including extracranial and intracranial disease, iatrogenesis, and depression. In approximately 20 per cent of cases, dementia is caused by a potentially reversible disease; in the remaining 80 per cent, it is associated with primary brain disease for which no specific treatment is yet known. In all cases, thorough medical and psychiatric evaluation is indicated. In a large percentage of cases of primary dementia, a multiple therapeutic approach, which includes psychopharmacologic and psychotherapeutic modalities, can arrest and sometimes reverse some of the debilitating complications of the dementing illness.