Table 2.

Descriptive Statistics of ADHD Symptoms throughout Development and Child Risk for ADHD.

	Variable	Mean (SD)	Range	n
Concurrent ADHD symptoms	Inattention symptoms T-score—17 y	53.37 (9.28)	40–77	63
	H/I symptoms T-score—17 y	58.56 (12.73)	43–87	63
	Inattention symptoms T-score—7 y	49.10 (7.52)	40–79	59
ADHD symptoms throughout childhood	H/I symptoms T-score—7 y	51.81 (8.22)	41–79	59
	Inattention symptoms—4.5 y	5.16 (3.21)	0–12.00	56
	H/I symptoms—4.5 y	6.73 (3.48)	1.00–16.00	56
Child risk for ADHD	Father’s inattention symptoms	11.31 (5.96)	0–25.00	61
	Father’s H/I symptoms	15.55 (7.59)	2.00–37.00	61
	Mother’s inattention symptoms	10.67 (5.50)	1.00–24.00	61
	Mother’s H/I symptoms	12.72 (6.02)	3.00–27.00	61
	Child’s effortful control—36 months	9.64 (1.55)	6.16–13.66	57

ADHD = attention-deficit hyperactivity disorder; H/I = hyperactivity-impulsivity.