TABLE 1:

Mean age, verbal intelligence, and SDS in each age group

Age group (y)	50–59	60–69	70–79
Number (M:F)	10 (4:6)	12 (7:5)	9 (5:4)
Mean age (y)	55.2 ± 3.0	63.8 ± 2.9	73.2 ± 2.4
Okabe’s Scale, total	48.9 ± 3.0	47.0 ± 5.7	45.4 ± 6.9
Information	18.4 ± 1.6	17.5 ± 1.7	16.4 ± 1.9
Mental control	14.5 ± 1.6	12.4 ± 3.3	12.8 ± 2.9
Digit span	9.0 ± 1.6	8.9 ± 1.5	9.2 ± 0.7
Associate learning	7.0 ± 3.9	8.2 ± 3.6	7.0 ± 3.6
SDS	30.8 ± 5.9	28.9 ± 4.3	29.7 ± 5.7

Note.—Okabe Scale indicates Okabe’s Simplified Intelligence Scale (60-point scale); SDS, Zung Self-Rating Depression Scale (80-point scale).