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How Psychiatrists Diagnose Alzheimer's Disease

    Although the family's primary care doctor is usually the first to diagnose or suspect a dementia, often it is a psychiatrist who makes the formal diagnosis of alzheimer's disease. For example, signs and symptoms of depression can be very similar to those of dementia. Dementia sometimes has been mistaken for schizophrenia. For example, hallucinations, delusions and other bizarre behaviors occur in both severe alzheimer's disease and schizophrenia. There are other subtle differences between depressed patients and alzheimer patients that only a psychiatrist may pick up. Patients diagnosed with depression tend to be more concerned about their memory loss and tend to come by themselves to the psychiatrist's appointment, whereas demented patients show less concern about their memory loss, tend to refuse treatments to help memory loss and usually come to the psychiatrist with their caregiver.     Psychiatrists tend to use the Mini Mental State Exam to diagnose alzheimer's and dementia. It is a test they use often in diagnosis, because they are very familiar with it. Once a psychiatrist suspects alzheimer's or other dementia, the diagnostic focus is on finding what is causing the dementia. Since more than 100 physical disorders can cause dementia symptoms, diagnosing the cause is very important. Other tests, such a neurologic exam, further neuropsychological tests, physical exam and laboratory blood and urine tests are often ordered to assist in the diagnosis. Psychiatrists sometimes find dementias that can be reversed. For example, obstructive sleep apnea causes problems with memory, thinking and attention, like those seen in early dementia. Yet, when the obstructive sleep apnea is diagnosed and corrected with therapy, the problems of memory, thinking and attention disappear. Psychiatrists often correctly diagnose vascular dementia. Psychiatrists use a test called the Hachinski Scale, which measures signs and sumptoms of vascular dementia. The Hachinski scale helps the diagnosis vascular dementia. Also useful for diagnosis are fluctuating memory loss, prior strokes, focal neurologic signs, stepwise deterioration and preservation of basic personality.