Table 1 Demographic characteristics of the subjects

Age

63.9 ± 8.3

61.3 ± 7.4

67.3 ± 7.9^a

72.6 ± 6.7^a

< 0.001

Amount of education

10.8 ± 2.2

11.3 ± 2.0

10.1 ± 2.2^a

9.1 ± 2.2^a

< 0.001

MMSE score

27.8 ± 2.6

28.3 ± 2.1

27.1 ± 2.8^a

25.6 ± 3.5^a

< 0.001

CES-D score

9.7 ± 6.1

9.5 ± 6.1

10.0 ± 6.3

10.0 ± 5.3

0.536

Apathy scale score

13.9 ± 6.3

13.4 ± 6.2

14.6 ± 6.5^a

15.2 ± 6.4^b

< 0.05