Table 1.

Demographic and clinical characteristics of the participants^*

	Group; mean ± SD†			Patient subgroup; mean ± SD†
Characteristic	Controls n = 30	Schizophrenia n = 39	p value	Antipsychotic-free, n = 13	Clozapine n = 10	Haloperidol n = 16	p value
Age, yr; mean (range)	24.57 (18–31)	23.87 (18–35)	0.47	25.5 (20–35)	22.2 (18–32)	22.63 (18–32)	0.21
Education, yr	11.8 ± 0.41	10.46 ± 0.85	< 0.001	10.5 ± 0.88	10.8 ± 0.92	10.19 ± 0.75	0.19
PANSS
Positive		14.2 ± 5.6	—	17.3* ± 4.6	12.5 ± 7.1	12.8 ± 4.5	0.047
Negative		18.3 ± 6.1	—	17.9 ± 4.8	17.8 ± 7.1	19.0 ± 6.7	0.86
General		31.0 ± 6.9	—	33.8 ± 8.0	27.8 ± 7.0	30.7 ± 5.0	0.11
Total		63.5 ± 14.9	—	69.0 ± 14.9	58.1 ± 18.4	62.4 ± 11.5	0.21
Duration of illness, mo.		21.8 ± 16.2		21.85 ± 18.8	30.6 ± 16.5	16.2 ± 11.4	0.08
Range		1–60	—	1–60	6–54	1–38	—
CPZ equivalents					353 ± 132	223 ± 62	0.013
DDD					0.88 ± 0.32	0.46 ± 0.12	0.002

CPZ = chlorpromazine; DDD = defined daily dose; PANSS = Positive and Negative Symptoms Scale; SD = standard deviation.

^*Differences between controls and patients with schizophrenia were assessed using the Student t test. Differences among patient subgroups were assessed using univariate analyses of variance.

^†Unless otherwise indicated.