Association
between history of depression and high risk of
Alzheimer's disease in men
Depressive
symptoms are common in patients with dementia or
Alzheimer's disease (AD), particularly in the
early stages. Conversely, mild cognitive
impairment observed in non-demented depressed
elderly subjects can often develop into
dementia. Many studies are controversial and
although evidence supports a link between
depression and increased risk for dementia and
AD, it is still uncertain whether depression is
an early prodrome or a risk factor. A study
examined the relationship between premorbid
symptoms of depression and the development of
dementia and AD over a period of 14 years.
The 1357 participants (576 women, 781 men)
completed the Center for Epidemiologic
Study-Depression (CES-D) Scale to assess the
frequency and severity of depressive symptoms,
every 2 years. Time-dependent, proportional
hazards to examine risk for AD associated with
depressive symptoms, detected at 2, 4, and 6
years of intervals before onset of dementia
symptoms, was calculated separately for men and
women.
For women,
49
cases of dementia were diagnosed (40 were AD),
and 76 men were diagnosed with dementia (67 were
AD). For women, there were no significant risks
at any time lag, for any dementia or AD
associated with CES-D scores. For men, the risk
was significantly greater with CES-D scores
indicating depressive symptoms at any time lag.
This risk in these men was about two times
higher than in those without a history of
depression.
These findings show that there is an influence
of depression on risk of developing dementia and
AD, later in life, this risk being greater in
men than in women. Since the prevalence of
depression is high and longevity is increasing,
their consequences on the health and economy
fields must be seriously considered and should
lead to an early diagnosis and thus an effective
treatment. Dal
Forno G, Palermo MT, Donohue JE, Karagiozis H,
Zonderman AB, Kawas CH. Depressive symptoms,
sex, and risk for Alzheimer's disease. Ann
Neurol 2005, 57: 381-387.