. Author manuscript; available in PMC: 2010 Jul 16.

Published in final edited form as: Psychosom Med. 2008 Dec 10;71(2):152–158. doi: 10.1097/PSY.0b013e31819082ef

TABLE 5.

Parameter Estimates From the Best Fitting Bivariate Models for Depressive Symptoms and IL-6

Traits	a² (95% CI)	e² (95% CI)	r_G (95% CI)	r_E (95% CI)
Unadjusted
BDI	0.49 (0.24–0.68)	0.51 (0.32–0.76)	0.22 (0.002–0.53)	0.11 (−0.03–0.35)
IL-6	0.39 (0.13–0.59)	0.61 (0.41–0.87)
Adjusted^a
BDI	0.51 (0.25–0.70)	0.49 (0.30–0.75)	0.27 (0.03–0.62)	0.02 (−0.08–0.25)
IL-6	0.44 (0.17–0.64)	0.56 (0.36–0.83)

BDI = Beck Depression Inventory; IL = interleukin; CI = Confidence Interval; a² = additive genetic influence (heritability); e² = unique environmental influence.

r_G = correlation between BDI and IL-6 due to genetic factors.

r_E = correlation between BDI and IL-6 due to unique environmental factors.

Adjusted for Framingham Risk Score, waist-hip ratio, and physical activity. Further adjustment for pack-years, marital status, and education did not substantially affect the study estimates.