Table 1 Demographics of participants

Number of participant

45

30

Sex

Male: 27

Male: 18

Age

50.6 ± 12.6

45.5 ± 13.0

Number of smoker

15

8

Duration of illness (years), mean ± SD

27.3 ± 12.8

CP equivalent dose (mg/day), mean ± SD

667.58 ± 635.28

l-serine (μM), mean ± SD

91.2 ± 21.1

85.6 ± 22.4

d-serine (μM), mean ± SD

1.50 ± 0.42

1.37 ± 0.45

Glycine (μM), mean ± SD

194.9 ± 64.0

176.5 ± 49.6

Vitamin B12 (pg/mL), mean ± SD

348.7 ± 132.6

309.5 ± 154.0

Folate (ng/mL), mean ± SD*

4.4 ± 1.7

5.7 ± 2.7

Homocysteine (μM), mean ± SD**

13.4 ± 8.3

9.1 ± 2.6

Methionine (μM), mean ± SD

13.1 ± 5.3

11.2 ± 7.1

PANSS score, mean ± SD

72.7 ± 17.9

Positive, mean ± SD

14.4 ± 5.4

Negative, mean ± SD

23.0 ± 6.0