Table 2.

Descriptive stats on longitudinal methylation sample

	Total	Childhood DNAm age	Adult DNAm age	Change in DNAm age
	% (N)	M (SD)	M (SD)	M (SD)
Mean Age	--	15.0 (2.3)	23.1 (2.8)	8.2 (3.3)
Female	51.4 (196)	15.1 (2.3)	23.2 (2.8)	8.0 (3.2)
Male	48.6 (185)	14.8 (2.3)	23.0 (2.8)	8.3 (3.4)
White	64.3 (245)	14.9 (2.3)	23.1 (2.8)	8.2 (3.2)
Black	4.7 (18)	15.0 (1.9)	23.9 (3.7)	8.9 (4.4)
American Indian	31.0 (118)	15.1 (2.3)	23.0 (2.7)	7.9 (3.2)

Overall N=381. Average chronological age at childhood obs = 13.9 (SD=1.6). Average chronological age at adult obs = 24.6 (SD=3.6).