ApoE4 is not associated with depression when mild cognitive impairment is considered.
OBJECTIVE
The aim of the study was to examine the relationship between apolipoprotein E4 allele (ApoE4) and depression among an older Japanese population. Mild cognitive impairment (MCI) was taken into consideration.


METHODS
This is a community-based cross-sectional study. We assessed the mood and cognitive function of Japanese community-dwelling individuals aged 65 years or older. In the first phase of the study, we evaluated the mood and cognitive function. In the second phase, face-to-face structured interviews were conducted. Individuals with dementia and other mental diseases were excluded on the basis of a consensus meeting of psychiatrists and neuropsychologists; 738 subjects with full data were included in the analyses. We subdivided depression into major depressive episode (MDE) and depressive symptoms cases (DSCs). DSC was defined as a score of 6 or more on the Geriatric Depression Scale but not having a diagnosis of MDE. The relationship between depression (MDE and DSC) and ApoE4 was examined by multivariate logistic regression.


RESULTS
The adjusted odds ratio (OR) of ApoE4 on DSC was not significant (OR = 0.82, 95%CI = 0.48-1.39, p < 0.46). Sex (OR = 2.53, 95%CI = 1.33-4.79, p < 0.01), MCI (1.95, 1.21-3.14, p < 0.01), years of education (0.87, 0.79-0.95, p < 0.01), and Nishimura's activities of daily living scores (0.75, 0.63-0.89, p < 0.01) significantly correlated with prevalence of DSC. There were no significant risk factors for MDE.


CONCLUSIONS
Apolipoprotein E4 allele contributed to neither DSC nor MDE. The association of MCI with ApoE4 and DSC suggested that MCI is a confounder for the association between ApoE4 and DSC.
Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba City, Japan.
Mayumi
M
Nose
Chiine
C
Kodama
Chiaki
C
Ikejima
Katsuyoshi
K
Mizukami
Asaki
A
Matsuzaki
Shiro
S
Tanaka
Atsuko
A
Yoshimura
Fumihiko
F
Yasuno
Takashi
T
Asada
D000339:Affect; D000368:Aged; D000369:Aged, 80 and over; D053327:Apolipoprotein E4 / Q000235:genetics*; D060825:Cognitive Dysfunction / Q000235:genetics* / Q000523:psychology; D003430:Cross-Sectional Studies; D003866:Depressive Disorder / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D012307:Risk Factors
D053327:Apolipoprotein E4