Objective. This study examined whether dementia patients with greater cognitive reserve had
increased mortality rates, and whether this association was different across strata of cognition,
functional ability and depression.
Methods. In the community-based Amsterdam Study of the Elderly, 261 non-institutionalized
dementia patients, identified using the Geriatric Mental State Schedule (GMS), were followed for an
average of 55·5 months after which mortality data were obtained. Cognitive reserve was indicated
by years of education and pre-morbid intelligence (measured using the Dutch Adult Reading
Test). Cognition, functional ability and depression were indicated by Mini-Mental State scores,
ADL and IADL measurements and GMS depressive syndrome, respectively.
Results. During the follow-up 146 persons (55·9%) died. Cox regression analyses showed that more
highly educated dementia patients had higher mortality rates, only if they had low MMSE scores
or if they had a concurrent depression. Pre-morbid intelligence was associated with a higher
mortality rate, independent of cognition, but this association was much stronger among patients
with depression. The positive association between education or intelligence and mortality was not
modified by functional disabilities.
Conclusions. The results suggest that dementia patients with greater cognitive reserve have
increased mortality rates, only if the disease has progressed to such an extent that clinical symptoms
are more severe. In this respect, the reserve hypothesis needs a modification. Depression in
dementia patients with greater cognitive reserve may reflect a subgroup of patients with poor