Thus, an awareness of early warning signs of dementia and an ability to distinguish the myriad other causes from Alzheimer's disease are critical. Since no confirmatory test is available, Alzheimer's disease remains a diagnosis of exclusion. Thus, the burden is on the physician to rule out other, treatable and even preventable forms of dementia or problems that resemble dementia. Drug use Perhaps the most common cause of reversible dementia is the use of certain drugs. Although oral preparations are most often implicated, eyedrops with beta-adrenergic or anticholinergic properties have also been reported to cause cognitive changes.
Depression is the most common such problem affecting the elderly.
History taking may provide the clues necessary to make a proper diagnosis, but at times, psychological testing or even a trial of antidepressant therapy may be necessary. In addition, depression may coexist with another cause of dementia, such as early Alzheimer's disease. In general, dementia caused by depression usually has an abrupt onset and is self-limited. In contrast, patients with Alzheimer's disease try to respond but provide inappropriate answers. In addition, somatic complaints are more common in persons with depression.