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Association between mid-life marital status and cognitive function in later life: population based cohort study

BMJ 2009; 339 doi: (Published 02 July 2009) Cite this as: BMJ 2009;339:b2462

Marital status and the risk of dementia

Hakansson et al (1) reported that for Finnish people in middle age losing a
spouse would have a substantial increase in the incidence of cognitive
impairment and dementia in later life, and the increased risk was higher
than those never married. The authors suggested that other factors, not
covered in the study, could partly explain this. The mid-life widowed,
compared to those married without premature death in middle age, might
have lived in a family environment with higher levels of risk factors,
including low income, cardiovascular and psychosocial factors and low
social support. Long-term widow status would make these situations worse,
increasing the risk of ill health.

In a population-based cohort study in China I examined the risk of
dementia in relation to marital status. Using a standardised method of the
Geriatric Mental State (GMS) interview (2), we recorded baseline mental
status, physical health and risk factors among 3336 elderly living in
urban and rural Anhui (3, 4). The prevalence of any depressive cases and
subcases, diagnosed by the GMS-AGECAT (3, 4), was 6.7% in married people
(n=2397), 10.1% in the widowed/divorcees (n=824, including 14 divorcees)
and 11.3% in the never-married (n=115) (p=0.002). In 2007-9, we re-
interviewed 1757 surviving cohort members. The incidence of dementia cases
and subcases (mild cognitive impairment) were diagnosed over a 7 year
period (5). Among participants with at least minimal educational levels,
whose data on dementia diagnosis were comparable to those in western
populations, I found that incident dementia (n=80) was related to baseline
marital status. After adjustment for age, sex, body mass index, urban-
rural region, educational levels, family income, smoking habits,
hypertensive status, stroke, frequency of contacting neighbours and the
GMS-AGECAT anxiety and depressions, odds ratio (OR) for dementia was 1.22
(0.67-2.25) in the widowed/divorcees and 5.32 (95%CI 1.14-24.8) in the
never-married in comparison with those married. The matched figures for
dementia subcases (n=169) were 1.31 (0.83-2.06) and 2.40 (0.63-9.22).

In such an older population which were absolutely poor but had high
levels of social support and low levels of depression and cardiovascular
risk (4), the finding that the risk of dementia significantly increased
with being single, but not being widowed (multiple adjusted OR 1.23, 0.67-
2.26), further supports the concept of the brain reserve hypothesis. The
current data, together with an increasing proportion of never-married
people in both developed and developing countries, additionally predicts a
potential epidemic of dementia in the world.

(1) Hakansson K, Rovio S, Helkala EL, Vilska AR, Winblad B, Soininen
H et al. Association between mid-life marital status and cognitive
function in later life: population based cohort study. BMJ 2009;

(2) Copeland JR, Prince M, Wilson KC, Dewey ME, Payne J, Gurland B.
The Geriatric Mental State Examination in the 21st century. Int J Geriatr
Psychiatry 2002; 17(8):729-732.

(3) Chen R, Hu Z, Qin X, Xu X, Copeland JR. A community-based study
of depression in older people in Hefei, China--the GMS-AGECAT prevalence,
case validation and socio-economic correlates. Int J Geriatr Psychiatry

(4) Chen R, Wei L, Hu Z, Qin X, Copeland JR, Hemingway H. Depression
in older people in rural China. Arch Intern Med 2005; 165(17):2019-2025.

(5) Chen R, Hu Z, Wei L, Qin X, McCracken C, Copeland JR. Severity of
depression and risk for subsequent dementia: cohort studies in China and
the UK. Br J Psychiatry 2008; 193(5):373-377.

Competing interests:
None declared

Competing interests: No competing interests

22 July 2009
Ruoling Chen
Centre for Health and Social Care improvement, School of Health and Wellbeing, University of Wolverh