ALZHEIMER'S DISEASE (AD)

According to the American Psychiatric Association, de-mentia (Latin "de"=loss of, "mens"= mind) of the Alzheimer type is diagnosed in the presence of the following cognitive (thinking, mental) deficits: (text below is a literal citation, but explanatory [bold print in brackets] is ours. Source: "Diagnostic and Statistical Manual of Mental Disorders", DMS-IV, 4th (newest) edition, published by the American Psychiatric Association, Washington D.C.,1994, p. 142)

A. The development of multiple cognitive [mental] deficits manifested by

1. memory impairment (impaired ability to learn new information or recall previously learned information)
2. one or more of the following cognitive disturbances
   1. aphasia (language disturbance)
   2. apraxia (impaired ability to carry out motor activities [purposeful movements] despite intact motor function [no physical handicap]
   3. agnosia (failure to recognize or identify objects despite intact sensory function) [no problem seeing, hearing, sensing by touch]
   4. disturbance in executive functioning (i.e., planning, organizing, sequencing, abstracting) [plan and execute actions]

B. The cognitive deficits in Criteria A1 and A2 each cause significant impairment in social or occupational functioning and represent a significant decline from a previous level of functioning

C. The course is characterized by gradual onset and continuing cognitive decline

D. The cognitive deficits in Criteria A1 and A2 are not due to any of the following

1. other central nervous system conditions [brain diseases] that cause progressive deficits in memory and cognition [thinking] (e,g., cerebrovascular disease [disease preventing adequate blood flow to brain], Parkinson's disease, Huntington's disease, subdural hematoma [expanding blood clot compressing brain], normal-pressure hydrocephalus [enlarged brain cavities reflecting loss of brain tissue through uncertain mechanism], brain tumor
2. systemic [involving body as a whole] conditions that are known to cause dementia (e.g., hypothyroidism [lack of thyroid hormone], vitamin B12 or folic acid deficiency, niacin deficiency, hypercalcemia [elevated free calcium levels in blood], neurosyphilis [form of syphilis progressively destroying brain and spinal cord], HIV infection)
3. substance-induced conditions [disturbed brain function from taking brain-active drugs such as alcohol, cocaine, drugs prescribed to treat mental illness]

E. The deficits occur not exclusively during the course of a delirium [rapidly developed confusion, restlessness, partial unresponsiveness, often provoked by intake or sudden withdrawal of alcohol/drugs, infection/fever, or biochemical/hormonal imbalances]

F. The deficit is not better accounted for by another Axis I disorder (e.g., major depressive disorder, schizophrenia) [Axis I refers to a classification by American Psychiatric Association; end of literal citation]

Onset of symptoms before or after the age of 65 is arbitrarily defined as "early onset" or "late onset" Alzheimer's disease (abbreviated EOAD, LOAD)..

Briefly, Alzheimer's disease begins with short-term memory deficits and progresses to language problems, social withdrawal, and decreased ability to carry out daily activities.

Depending upon diagnostic criteria, about 2-4 out of 280 million Americans (0.5-1.5%) suffer from Alzheimer's.

According to the Cardiovascular Health Study (CHS) (Neuroepidemiology 2003,volume 22, pages 1-12) evaluating 5,888 US citizens over the period 1991-2000, about 33% of Americans above age 65 exhibited mental (cognitive) impairment, but the prevalence (number of cases in population sample at a given time point) of obvious dementia was only 6.3%. Cause of dementia in the same study was ascribed to Alzheimer's disease in about 69% of cases. Other causes were mixed vascular/Alzheimer dementia in 16%, vascular dementia in 11%, and other types in 4%.

Prevalence increases as life expectancy of Americans increases. Above age 80, as many as 40-50% of US citizens exhibit signs of Alzheimer's disease

Alzheimer-related annual economic burden in US exceeds 150 billion dollars.