Table 2.

Baseline comparisons among three subgroups based on depression status

Depression status	None n = 155	Non-amyloid n = 36	Amyloid-associated n = 32	P value
Follow-up, year, mean ± SD	6.2 ± 0.7	6.1 ± 0.5	6.2 ± 0.6	0.67
Age, year, mean ± SD	72.6 ± 7.7	68.0 ± 6.6	72.3 ± 8.0	0.002
Female, n/total (%)	125/155 (81%)	29/36 (81%)	27/32 (84%)	0.88
High school and above, n/total (%)	121/155 (78%)	24/36 (67%)	26/32 (81%)	0.13
African Americans, n/total (%)	44/155 (28%)	12/36 (33%)	8/32 (25%)	0.78
ApoE4, n/total (%)	37/153 (24%)	7/36 (19%)	5/31 (16%)	0.55
Diabetes, n/total (%)	41/153 (27%)	13/35 (37%)	8/32 (25%)	0.42
Cardiovascular disease, n/total (%)	57/150 (38%)	11/35 (31%)	12/31 (38%)	0.75
Stroke, n/total (%)	19/153 (12%)	5/36 (13%)	3/31 (10%)	0.87
Antidepressant usage, n/total (%)	45/154 (28%)	21/36 (58%)	14/32 (44%)	0.002
MMSE score, mean ± SD	27.0 ± 2.3	26.4 ± 3.1	26.6 ± 3.1	0.43

No depression was defined by having a CES-D score < 16, non-amyloid depression was defined by having a CES-D score ≥ 16 and plasma Aβ40/Aβ42 ratio ≤ 7.1 and amyloid-associated depression was defined by having a CES-D score ≥ 16 and plasma Aβ40/Aβ42 ratio > 7.1. Mean ± SD with ANOVA test or n/total (%) with Chi Square test are presented. P values for statistical significance are shown. MMSE = Mini-Mental State Exam.