ADHD genetic burden associates with older epigenetic age: mediating roles of education, behavioral and sociodemographic factors among older adults

Table 4 Unstandardized direct and indirect effects of the ADHD polygenic score (ADHD-PGS) on GrimAge for the multi-mediation model

Predictor or mediator	Path a1: ADHD-PGS → mediator	Path a2: Education → mediator	Path b: Mediator → GrimAge	Path a1*b: Indirect effects: ADHD-PGS → mediator → GrimAge	Path a2*b: Indirect effects: education → mediator → GrimAge	Path a1–a2–b: Indirect effects: ADHD-PGS → education → mediator → GrimAge	Path c: Direct effects: on GrimAge
Predictor or mediator	Beta (SE)	Beta (SE)	Beta (SE)	Beta (SE)	Beta (95% CI)	Beta (95% CI)	Beta (SE)
ADHD-PGS							0.222 (0.080)**
Smoking	1.134 (0.477)*	− 1.745 (0.202)***	0.077 (0.003)***	0.087 (0.026, 0.150)*	− 0.134 (− 0.163, − 0.106)**	0.036 (0.024, 0.050)***
Depressive symptoms	0.086 (0.033)*	− 0.087 (0.014)***	0.214 (0.052)***	0.018 (0.005, 0.035)*	− 0.019 (− 0.029, − 0.010)**	0.005 (0.002, 0.009)**
Body Mass Index	0.125 (0.115)	− 0.258 (0.049)***	0.046 (0.015)***	0.006 (− 0.002, 0.016)	− 0.012 (− 0.019, − 0.005)**	0.003 (0.001, 0.005)*
Education	− 0.269 (0.048)***			0.055 (0.032, 0.081)***			− 0.204 (0.038)***
Cognition	− 0.180 (0.069)**	0.470 (0.030)***	− 0.047 (0.024)#	0.008 (0.000, 0.019)	− 0.022 (− 0.042, − 0.002)#	0.006 (0.001, 0.012)#
Income	− 0.018 (0.018)	0.133 (0.008)***	− 0.231 (0.095)#	0.004 (− 0.003, 0.012)	− 0.031 (− 0.052, − 0.010)*	0.008 (0.002, 0.015)*
Total Indirect Effect for ADHD-PGS to GrimAge						0.237 (0.165, 0.313)***
Total indirect effect for education to GrimAge					− 0.217 (− 0.257, − 0.178)***

SE = standard error, 95% CI = 95% confidence interval, estimated from a bias-corrected bootstrap procedure with 5000 draws
^#p < .10; *p < .05; **p < .01; ***p < .001. Total effect from ADHD-PGS to GrimAge: β = 0.459, SE = 0.090, p < .0001. Total effect from Education to GrimAge: β = −0.421, SE = 0.038, p < .0001

ISSN: 1868-7083