Association of serum interleukin-6 with negative symptoms in stable early-onset schizophrenia

Table 1 Demographic and clinical characteristics of early-onset schizophrenia patients, adult-onset schizophrenia patients, and healthy controls

	Early-onset schizophrenia	Adult-onset schizophrenia	Healthy control	Statistic (F/χ2)	P value
Sex
Male	23	24	23	1.57	0.461
Female	10	17	18
Smoking
Smoker	7	13	15	2.09	0.351
Nonsmoker	26	28	26
Age (yr)a	38.79 ± 9.21	46.14 ± 7.26	42.61 ± 10.30	5.00	0.0082
Educations (yr)b	9.64 ± 2.50	9.10 ± 2.96	12.24 ± 2.61	20.78	< 0.0012
BMI (kg/m2)b	28.57 ± 4.87	25.56 ± 3.74	23.26 ± 2.72	17.88	< 0.0012
Age of onset (yr)b	17.00 ± 2.75	28.22 ± 5.69		107.67	< 0.0012
Duration of illness (yr)	21.61 ± 9.22	17.88 ± 7.29		3.78	0.0562
Dose of CPZ equivalent (mg/d)	653.37 ± 300.04	704.85 ± 311.41		0.52	0.4752
PANSS
Positive subscores	14.54 ± 5.95	14.73 ± 6.71		1.60	0.213
Negative subscoresa	20.85 ± 5.56	18.15 ± 3.86		6.20	0.0153
General subscores	33.21 ± 9.32	31.05 ± 8.24		0.16	0.6883
Total scores	68.61 ± 17.90	63.93 ± 14.23		0.004	0.9533
Expressive deficits	16.33 ± 4.77	14.17 ± 3.26		3.26	0.0753
Avolition/asociality	9.52 ± 3.72	8.44 ± 2.44		2.05	0.1573
Log IL-6 levelb	0.88 ± 0.37	0.81 ± 0.40	0.18 ± 0.03	22.32	< 0.0013

^aP < 0.05.

^bP < 0.001.

¹χ² test.

²One-way analysis of variance.

³The P values for Positive and Negative Symptom and log interleukin-6 were adjusted for age, sex, and body mass index.

Mean ± SD are reported for all variables. BMI: Body mass index; CPZ: Chlorpromazine; PANSS: Positive and Negative Symptom; IL-6: Interleukin-6.