Light treatment for seasonal Winter depression in African-American vs Caucasian outpatients

Table 1 Characteristics of the participants in the two groups n (%)

Variable	African-Americans (n = 51)	Caucasians (n = 27)	P-value1
Age, yr, mean ± SD	43.1 (10.3)	47.0 (10.1)	0.11
Gender male	19 (37.3)	14 (51.9)	0.21
Bipolar II diagnosis	2 (3.9)	1 (3.7)	0.96
Education: High school or less	26 (52.0)	7 (25.9)	0.03
Marital status
Married or cohabiting	7 (14.0)	5 (18.5)	0.42
Widowed, divorced, or separated	12 (24.0)	11 (40.8)	0.19
Never married	31 (62.0)	11 (40.7)	0.15

¹P-values from t-test comparing races on age; χ² for other variables.

Table 2 Comparison of pretreatment and post-treatment depression scores

Variable	African-Americans	Caucasians	P-value1
Pre-treatment mood scores	(n = 51)	(n = 27)
SIGH-SAD, mean ± SD	33 (6.9)	31 (6.4)	0.22
BDI-II, mean ± SD	25 (10.9)	23.6 (8.4)	0.58
Post-treatment mood scores	(n = 41)	(n = 24)
SIGH-SAD, mean ± SD	9.31 (6.9)	6.79 (6.0)	0.15
BDI-II, mean ± SD	9 (7.9)	7.3 (7.4)	0.41

¹P-values from t-test compare the two groups on pre-treatment and post-treatment depression scores. SIGH-SAD: Structured Interview Guide for Hamilton-Seasonal Affective Disorder version; BDI-II: Beck Depression Inventory Second Edition.

Table 3 Response, remission, and depression score changes by groups

Variable	African-Americans (n = 41)	Caucasians (n = 24)	P-value1
Response, 50% reduction SIGH-SAD, n (%)	33 (80.5)	20 (83.3)	0.78
Remission, SIGH-SAD < 8, n (%)	19 (46.3)	18 (75.0)	0.02
SIGH-SAD, % change, mean ± SD	-70.4 (22.7)	76.0 (22.6)	0.34
BDI-II, % change, mean ± SD	-61.8 (32.2)	-68.1 (32.9)	0.46
POMS-A, % change, mean ± SD	-46.6 (46.7)	-46.8 (48.8)	0.98
POMS-D, % change, mean ± SD	-52.7 (47.1)	-49.2 (54.9)	0.78
Treatment days missed, mean ± SD	8.7 (11.0)	7.4 (8.3)	0.61
Percent adherence, mean ± SD	79.4 (26.2)	82.4 (19.7)	0.61

¹P-values from t-test comparing races on age; χ² for other variables. SIGH-SAD: Structured Interview Guide for Hamilton-Seasonal Affective Disorder version; BDI-II: Beck Depression Inventory Second Edition; POMS-A: Profile of Mood States-Anxiety; POMS-D: Profile of Mood States-Depression.

Table 4 Adjusted mean changes in depression score outcomes in African-Americans and Caucasians, adjusted for adherence, age, education and gender

Variable	African-Americans (n = 41)	Caucasians (n=24)	P-value1
Mood scale
SIGH-SAD	-22.9 (1.6)	-25.2 (2.1)	0.41
BDI-II	-16.6 (2.0)	-16.4 (2.6)	0.95

¹P value from linear regression. SIGH-SAD: Structured Interview Guide for Hamilton-Seasonal Affective Disorder version; BDI-II: Beck Depression Inventory Second Edition.

Table 5 Sensitivity analysis including all participants n (%)

	African-Americans (n = 51)	Caucasians (n = 27)	P-value1
Remission, SIGH-SAD ≤ 8	19 (37.3)	18 (66.7)	0.01
Treatment days missed, mean ± SD	11.3 (13.9)	7.4 (8.3)	0.13
Percent adherence, mean ± SD	73.2 (33.1)	82.4 (19.7)	0.13

¹P-values from t-test comparing races on age; χ² for other variables. SIGH-SAD: Structured interview guide for the Hamilton-Seasonal Affective Disorder version.