Table 1.

Demographic and clinical characteristics of the study participants.

	Patients with SZ (N = 101)	HCs (N = 101)	Statistics	p
Sex
Male, n (%)	35 (34.7)	42 (41.6)	χ2 = 1.45	0.311
Female, n (%)	66 (65.3)	59 (58.4)
Age (years), mean ± SD	37.0 ± 11.5	37.9 ± 8.7	t = 0.63	0.521
Education (years), mean ± SD	13.0 ± 2.4	16.7 ± 2.5	t = 10.40	<0.001
Duration of illness (months), mean ± SD	46.3 ± 72.2
Intracranial volume (mL), mean ± SD	1466.9 ± 139.7	1543.5 ± 130.4	t = 4.01	<0.001
Antipsychotic medications at MRI scan (mg/day), mean ± SDa	435.3 ± 256.5
Antipsychotic medications at 6 months (mg/day), mean ± SDa	715.0 ± 1634.1
Duration of antipsychotic medication before scan of antipsychotic-naive or free participants (days), mean ± SD	6.8 ± 7.2
Types of antipsychotics
Paliperidone (n)	32
Olanzapine (n)	2
Risperidone (n)	27
Amisulpride (n)	32
Aripiprazole (n)	8
Full-scale intelligence quotient, mean ± SD	88.6 ± 18.5	114.9 ± 6.3	t = 4.23	<0.001
Verbal intelligence quotient	94.7 ± 16.2	117.0 ± 9.0	t = 7.41	<0.001
Information	9.3 ± 3.3	11.1 ± 2.5	t = 1.40	0.166
Digit span	8.5 ± 3.4	11.6 ± 1.7	t = 2.27	0.026
Vocabulary	9.2 ± 3.3	12.8 ± 1.1	t = 6.99	<0.001
Arithmetic	8.0 ± 2.9	12.1 ± 2.6	t = 2.93	0.004
Comprehension	9.9 ± 3.3	13.7 ± 0.9	t = 6.74	<0.001
Similarity	9.4 ± 3.4	13.9 ± 1.6	t = 2.73	0.008
Performance intelligence quotient	89.7 ± 17.5	110.7 ± 7.6	t = 7.72	<0.001
Picture completion	8.4 ± 2.9	10.1 ± 2.0	t = 4.51	<0.001
Picture arrangement	8.9 ± 2.9	11.0 ± 1.4	t = 2.02	0.049
Block design	8.6 ± 3.9	13.7 ± 1.6	t = 5.59	<0.001
Object assembly	9.2 ± 3.8	12.6 ± 2.1	t = 3.21	0.008
Digit symbol	9.0 ± 3.0	12.2 ± 1.2	t = 2.54	0.014

SZ schizophrenia, HCs healthy controls, SD standard deviation, MRI magnetic resonance imaging.

^aChlorpromazine equivalent doses were calculated according to Gardner et al.⁶¹.