Table 1.

Characteristics of participants by diagnostic cohort

Demographic variable	Depressed (N= 130)	Nondepressed (N=110)	Test statistic	P value
Age	69.9 (7.0)	70.2 (5.8)	T=0.28, 238 df	0.7759
Sex, % female	62.31% (81)	70.00% (77)	X2= 1.57, 1df	0.2106
Race, % Caucasian	89.23% (116)	81.8% (90)	X2 = 2.69, 1df	0.1008
Hypertension	43.08% (56)	22.73% (25)	X2= 11.04, 1df	0.0009
Diabetes	3.9% (5)	8.25 (9)	Fisher’s exact	0.1688
Heart Disease	16.9% (22)	8.25 (9)	X2= 3.64, 1df	0.0564
MMSE	28.27 (2.6)	28.95 (1.2)	T= 2.69, 187.86 df	0.0077
Baseline MADRS	26.92 (7.3)	---
MRI WMH Volumes
WMH baseline (log ml)	1.42 (0.84)	1.24 (0.78)	T=1.79, 238 df	0.0745
WMH baseline (ml)	6.70 (10.67)	5.18 (7.18)	T=1.31, 227 df	0.1911
WMH change (log ml)	0.17 (0.30)	0.20 (0.28)	T=0.81, 238 df	0.4216
WMH change (ml)	1.48 (3.38)	1.45 (3.13)	T=0.08, 238 df	0.9394
Stress measures
Baseline stressor exposure	2.42 (1.67)	1.18 (1.11)	T=6.81, 225.80 df	<0.0001
Change in stressor exposure	−0.64 (1.88)	−0.06 (1.63)	T=2.51, 238 df	0.0129
Baseline perceived stress severity	6.44 (2.00)	2.69 (1.47)	T=16.67, 231.91 df	<0.0001
Change in perceived stress severity	−1.57 (2.51)	−0.07 (1.53)	T=5.62, 214.27 df	<0.0001

Data presented as mean (standard deviation) for continuous variables, or percent (N) for categorical variables. All comparisons of continuous measures used pooled, two-tailed t-tests with 238 degrees of freedom (df), except for when variances were unequal, in which case Satterthwaite t-tests were used. Categorical comparisons used chi-square tables, aside from comparisons of reports of diabetes, which used Fisher’s exact test due to small cell samples. Medical morbidity (hypertension, diabetes, heart disease) presented as percent (N) who endorsed having these disorders. MMSE = mini-mental state exam; MADRS = Montgomery-Asberg Depression Rating Scale; WMH = white matter hyperintensity