Depressive symptoms and cognitive decline in community-dwelling older adults.
OBJECTIVE
To examine the temporal association between depressive symptoms and cognitive functioning and estimate the effect measure modification of the apolipoprotein E (APOE) epsilon4 allele on this relationship.


METHODS
Prospective cohort study.


METHODS
General community.


METHODS
Population-based sample of 598 cognitively intact older adults aged 60 and older, with re-assessments after 3 (N=479) and 6 years (N=412).


METHODS
Depressive symptoms (Symptom Checklist) and neurocognitive functioning (memory, Visual Verbal Learning Test; attention, Stroop Color-Word Test; processing speed, Letter Digit Substitution Test; general cognition, Mini-Mental State Examination). Longitudinal associations were assessed using linear mixed models. The risk for cognitive impairment, no dementia (CIND) was examined using logistic regression.


RESULTS
Adjusting for age, sex, education, and baseline cognition, the rate of change in memory z-scores was 0.00, -0.11, -0.20, and -0.37 for those in the lowest (reference group), second, third, and highest depressive symptom quartiles at baseline, respectively (P<.001 for highest vs lowest quartile). The odds ratios for developing CIND with amnestic features were 1.00, 0.87, 0.69, and 2.98 for the four severity groups (P=.05 for highest vs lowest quartile). Associations were strongest for those with persistent depressive symptoms, defined as high depressive symptoms at baseline and at least one follow-up visit. Results were similar for processing speed and global cognitive function but were not as strong for attention. No APOE interaction was observed.


CONCLUSIONS
Depression and APOE act independently to increase the risk for cognitive decline and may provide targets for prevention and early treatment.
Köhler
Sebastian
S
Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, European Graduate School of Neuroscience, Maastricht University, Maastricht, the Netherlands. s.koehler@np.unimaas.nl
van Boxtel
Martin P J
MP
van Os
Jim
J
Thomas
Alan J
AJ
O'Brien
John T
JT
Jolles
Jelle
J
Verhey
Frans R J
FR
Allardyce
Judith
J
D000368:Aged; D000369:Aged, 80 and over; D001057:Apolipoproteins E / Q000235:genetics; D003071:Cognition; D015331:Cohort Studies; D003863:Depression / Q000523:psychology*; D005094:Exophthalmos; D005260:Female; D005838:Genotype; D006801:Humans; D057187:Independent Living; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors
D001057:Apolipoproteins E