Table 2.

Relationship between white matter microstructure with age, sex, and pubertal stage.

Metric	Region	Model		AIC	Age		Sex		Pubertal stage
					β (95 % CI)	pFDR	β (95 % CI)	pFDR	β (95 % CI)	pFDR
FD	CCG	L	3	487.93	.13 [.08, .19]	< .001	.06 [−.31, .42]	.86	.05 [−.05, .14]	.54
		R	3	474.70	.10 [.04, .15]	.002	.10 [−.26, .46]	.75	.05 [−.04, .14]	.50
	CCH	L	3	603.95	−.02 [−.10, .07]	.85	−.27 [−.64, .12]	.32	−.15 [−.29, −.01]	.11
		R	5	614.16	−.04 [−.13, .05]	.54	−.23 [−.63, .14]	.43	−.01 [−.17, .16]	.97
	CST	L	3	596.69	.11 [.03, .20]	.04	−.41 [−.78, −.03]	.10	−.06 [−.20, .08]	.57
		R	3	549.74	.11 [.04, .18]	.02	−.41 [−.77, −.05]	.09	−.02 [−.14, .11]	.89
	Fmajor		1	428.71	.21 [.17, .24]	< .001	−.21 [−.55, .14]	.44	–
	Fminor		5	580.63	.16 [.08, .24]	.002	−.15 [−.53, .23]	.62	.01 [−.14, .16]	.91
	FX		3	500.20	.06 [.01, .12]	.10	−.17 [−.54, .19]	.54	−.04 [−.13, .06]	.62
	IFOF	L	3	564.38	.09 [.02, .17]	.05	−.13 [−.51, .24]	.67	.02 [−.10, .14]	.86
		R	3	566.07	.10 [.02, .17]	.06	−.32 [−.69, .04]	.20	.09 [−.04, .21]	.37
	ILF	L	3	564.88	.08 [.01, .15]	.10	−.14 [−.52, .24]	.63	.01 [−.12, .13]	.98
		R	5	542.20	.05 [−.02, .12]	.32	.10 [−.29, .48]	.77	.12 [−.01, .25]	.18
	SLF	L	3	449.63	.13 [.08, .17]	< .001	−.07 [−.44, .30]	.82	.01 [−.08, .08]	.95
		R	3	459.20	.10 [.06, .15]	< .001	.04 [−.34, .40]	.90	.12 [.03, .20]	.03
	UF	L	3	608.60	.05 [−.04, .14]	.51	.06 [−.30, .44]	.86	.04 [−.11, .18]	.77
		R	4	599.97	.01 [−.08, .09]	.96	−.06 [−.42, .32]	.86	−.05 [−.20, .11]	.72
FC	CCG	L	1	328.39	.11 [.08, .13]	< .001	.11 [−.20, .43]	.64	–
		R	1	334.71	.10 [.08, .13]	< .001	.22 [−.11, .55]	.39	–
	CCH	L	3	525.04	−.03 [−.10, .03]	.54	.28 [−.08, .65]	.30	.07 [−.04, .19]	.44
		R	3	491.79	.01 [−.05, .07]	.87	.04 [−.33, .41]	.91	.04 [−.06, .14]	.62
	CST	L	3	358.03	.19 [.15, .23]	< .001	−.34 [−.66, −.01]	.12	−.03 [−.10, .04]	.54
		R	3	334.06	.19 [.15, .23]	< .001	−.29 [−.59, .04]	.19	.03 [−.03, .10]	.52
	Fmajor		3	301.22	.12 [.09, .15]	< .001	−.38 [−.73, −.05]	.11	.01 [−.04, .06]	.87
	Fminor		5	327.30	−.01 [−.05, .03]	.78	−.30 [−.64, .05]	.20	.02 [−.05, .09]	.78
	FX		1	374.13	.07 [.03, .10]	< .001	.21 [−.10, .52]	.39	–
	IFOF	L	1	390.58	.08 [.04, .12]	< .001	−.15 [−.43, .14]	.53	–
		R	5	357.94	.06 [.02, .11]	.04	−.07 [−.36, .23]	.78	.06 [−.03, .15]	.41
	ILF	L	3	493.81	.03 [−.04, .10]	.54	.16 [−.18, .51]	.54	.12 [.01, .23]	.10
		R	5	429.17	.04 [−.02, .10]	.43	.15 [−.15, .46]	.54	.19 [.08, .30]	.006
	SLF	L	5	442.67	.11 [.06, .16]	< .001	.12 [−.19, .52]	.54	.16 [.01, .22]	.10
		R	3	428.74	.14 [.09, .19]	< .001	.22 [−.11, .57]	.41	.14 [.06, .23]	.009
	UF	L	1	445.80	.06 [.02, .10]	.03	.34 [.02, .66]	.11	–
		R	3	431.13	.05 [−.01, .11]	.16	.07 [−.26, .40]	.81	.01 [−.09, .10]	.97
FDC	CCG	L	1	427.43	.14 [.11, .18]	< .001	−.01 [−.37, .35]	.99	–
		R	3	437.83	.12 [.07, .17]	< .001	.16 [−.22, .53]	.56	.05 [−.04, .13]	.49
	CCH	L	3	604.84	−.03 [−.12, .05]	.62	−.08 [−.50, .33]	.84	−.09 [−.23, .05]	.43
		R	3	582.06	−.01 [−.08, .08]	.99	−.29 [−.71, .12]	.32	−.06 [−.19, .08]	.55
	CST	L	3	490.99	.19 [.13, .25]	< .001	−.43 [−.79, −.05]	.09	−.05 [−.16, .05]	.54
		R	3	468.85	.18 [.13, .24]	< .001	−.40 [−.77, −.04]	.10	.01 [−.08, .11]	.90
	Fmajor		1	338.21	.19 [.17, .21]	< .001	−.31 [−.69, .08]	.26	–
	Fminor		5	384.20	.07 [.03, .12]	.01	−.46 [−.79, −.13]	.03	−.01 [−.09, .09]	.99
	FX		3	482.25	.09 [.03, .14]	.02	−.08 [−.47, .31]	.82	−.01 [−.11, .09]	.91
	IFOF	L	3	505.27	.10 [.04, .17]	.02	−.18 [−.54, .19]	.54	.03 [−.09, .14]	.78
		R	3	489.83	.10 [.04, .17]	.01	−.30 [−.65, .06]	.23	.05 [−.06, .16]	.54
	ILF	L	3	536.65	.07 [−.01, .14]	.16	−.09 [−.48, .28]	.78	.07 [−.06, .19]	.49
		R	5	476.66	.05 [−.01, .11]	.26	.01 [−.36, .36]	.97	.18 [.07, .30]	.02
	SLF	L	3	432.95	.14 [.09, .18]	< .001	.04 [−.34, .40]	.91	.06 [−.02, .14]	.32
		R	3	451.14	.14 [.09, .19]	< .001	.19 [−.20, .57]	.54	.16 [.07, .24]	.003
	UF	L	3	540.59	.07 [−.01, .14]	.19	.17 [−.21, .55]	.55	.02 [−.10, .14]	.84
		R	3	515.73	.04 [−.03, .11]	.49	−.17 [−.52, .19]	.54	.02 [−.10, .13]	.88

Note: Best model fit was determined using the lowest AIC for all models tested within each region (see Table S1 for full model details). Total intracranial volume (TIV) was entered as a covariate for morphological measures (FC, FDC). Abbreviations: CCG = cingulum cingulate gyrus; CCH = cingulum hippocampus; CST = Cortico-spinal tract; FA = Fractional anisotropy; FC = Fibre cross-section; FD = Fibre density; Fmajor = Forceps major; Fminor = Forceps minor; FX = fornix; L = Left; IFOF = inferior fronto-occipital fasciculus; ILF = inferior longitudinal fasciculus; R = Right; SLF = Superior longitudinal fasciculus; UF = uncinate fasciculus. P-values were adjusted for false-discovery rate (p_FDR), where bold values denote p_FDR < .05.