Table 2.

Comparisons of the mean GFA values of the white matter tracts of the three groups (patients, siblings, and controls)

Fiber tract	Schizophrenic patients	Unaffected siblings	Healthy controls	ANCOVA	Posthoc LSD
					Patients versus controls	Siblings versus controls	Patients versus siblings
	GFA value Mean ± SD	GFA value Mean ± SD	GFA value Mean ± SD	P‐value	P‐value	P‐value	P‐value
Whole‐brain white matter tracts	0.285 ± 0.008	0.287 ± 0.010	0.290 ± 0.005	0.044a	0.018a	0.232	0.233
Rt. AF	0.262 ± 0.017	0.269 ± 0.017	0.278 ± 0.012	b0.043a	0.001a	c0.035a	0.108
Lt. FX	0.140 ± 0.026	0.170 ± 0.020	0.177 ± 0.015	b0.003a	<0.001a	0.205	<0.001a
Rt. FX	0.185 ± 0.025	0.211 ± 0.019	0.214 ± 0.015	b0.003a	<0.001a	0.593	<0.001a
Lt. AT	0.196 ± 0.011	0.200 ± 0.010	0.204 ± 0.010	b0.021a	0.005a	0.129	0.171
Rt. AT	0.199 ± 0.013	0.204 ± 0.014	0.209 ± 0.007	b0.021a	0.002a	0.100	0.136
Lt. OR	0.308 ± 0.015	0.316 ± 0.015	0.324 ± 0.015	b0.043a	<0.001a	0.057	0.047a
Genu of CC	0.294 ± 0.021	0.305 ± 0.022	0.314 ± 0.021	b0.021a	0.001a	0.136	0.055
CC to DLPFC	0.321 ± 0.018	0.332 ± 0.018	0.336 ± 0.015	b0.018a	0.001a	0.318	0.014a
CC to TP	0.186 ± 0.022	0.199 ± 0.015	0.205 ± 0.013	b0.018a	<0.001a	0.198	0.003a
CC to HP	0.176 ± 0.032	0.195 ± 0.018	0.201 ± 0.022	b0.027a	<0.001a	0.371	0.005a

^aStatistically significant.

^bA significant difference among three study groups was detected by ANCOVA test while controlling for age and sex and survived Benjamini–Hochberg correction for multiple comparisons (FDR = 0.05).

^cA significant difference between siblings and controls was detected by posthoc LSD test.

Abbreviations: Rt., right; Lt., left; AF, arcuate fasciculus; FX, fornix; AT, auditory tract; OR, optic radiation; CC, corpus callosum; DLPFC, dorsolateral prefrontal cortex; TP, temporal pole; HP, hippocampus; LSD, least significant difference.