Alzheimer's disease is characterised by the gradual but progressive lo
ss of memory and other cognitive abilities. Pathological features incl
ude the accumulation of neurofibrillary tangles, neuritic plaques and
beta-amyloid protein within vulnerable regions of the brain. A number
of actions of estrogen have the potential to affect brain function and
influence the pathology of Alzheimer's disease. Early-onset Alzheimer
's disease is a relatively infrequent disorder which is usually inheri
ted in an autosomal dominant manner. However, for late-onset illness,
it is likely that several genetic and environmental factors are pathog
enetically important. A number of epidemiological studies link postmen
opausal hormonal replacement therapy to a reduced risk of developing A
lzheimer's disease. Estrogen can affect cognition and mood, and a numb
er of generally small intervention trials suggest that estrogen improv
es cognitive skills among women with Alzheimer's disease. However, mos
t treatment studies have not been conducted in a methodologically rigo
rous fashion. There are no firm data on different estrogen preparation
s and dosages or on the role of progestins in the prevention and treat
ment of Alzheimer's disease in women, and no data support the use of e
strogen for this disorder in men.