Table 2.

Studies of developmental neurocognitive disorders including young children (under 6 years old, that contributed to the review.

Study	N	Ages	Measures	Study type
Autism Spectrum Disorder (ASD)
Nordahl et al., 2011	114 ASD (22F)	2–4yo	Brain volumes	Cross-sectional
	66 TD (24F)
Shen et al., 2013	41 HR	6–36mo	Brain volumes	Longitudinal
	23 LR
Hazlett et al., 2012	98 HR	6 mo	Brain volumes	Cross-sectional
	36 LR
Hazlett et al., 2017	106 HR	6–24mo	Brain volumes	Longitudinal
	42 LR		Cortical thickness
			Surface area
Attention deficit hyperactivity disorder (ADHD)
Castellanos et al., 2002	151 ADHD (63F)	4.5–19yo	Brain volumes	Longitudinal
	139 TD (56F)
Shaw et al., 2007	223 ADHD	4–25yo	Cortical thickness	Longitudinal
	223 TD
Shaw et al., 2009	218 ADHD	3–22yo	Cortical thickness	Longitudinal
	358 TD
Bora et al., 2014	110 preterm	4–9yo	Brain volumes	Cross-sectional
	113 full term
Yang et al., 2015	25 ADHD	5–12yo	Cortical thickness	Cross-sectional
	25 TD
Dyslexia (DYS)
Raschle et al., 2011	10 HR	5–6yo	Brain volumes	Cross-sectional
	10 LR
Black et al., 2012	27 HR (12F)	5–6yo	Brain volumes	Cross-sectional
	24 LR (10F)		Cortical thickness
			Surface area
Hosseini et al., 2013	22 HR (9F)	5–6yo	Brain volumes	Cross-sectional
	20 LR (11F)		Cortical thickness
			Surface area
			Connectivity
Clark et al., 2014	11 DYS	5–11 yo	Cortical thickness	Longitudinal
	16 TD
Im et al., 2016	15 HR	4–13 yo	Sulcal graph	Cross-sectional
	16 LR
	15 DYS
	13 TD
Vanderauwera et al., 2016	36 HR	5–6 yo	Surface area	Cross-sectional
	35 LR

TD, typical development; F, female; ASD, autism spectrum disorder; ADHD, attention deficit hyperactivity disorder; DYS, dyslexia; HR, high risk; LR, low risk; yo, years old; mo, months