J Neurol Res

Journal of Neurology Research, ISSN 1923-2845 print, 1923-2853 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Neurol Res and Elmer Press Inc

Journal website https://www.neurores.org

Original Article

Volume 11, Number 1-2, April 2021, pages 20-26

Nociceptive Reflex in Patients With Schizophrenia: A Case-Control Study

**Table 1.** Socio-Demographic Data of the Case and Control Groups
	Cases (n = 24)	Controls (n = 12)	Test of significance	P-value
χ²: Chi-square test. t: independent samples test. P value ≤ 0.05 is considered significant. P value < 0.001 is considered highly significant. SD: standard deviation.
Age (mean ± SD), years	27.54 ± 5.509	28.08 ± 5.418	t = 0.280	0.781
Gender			χ² = 0.00	1.000
Male, n (%)	14 (58.3)	7 (58.3)
Female, n (%)	10 (41.7)	5 (41.7)
Smoking			χ² = 0.223	0.637
Smoker, n (%)	12 (50)	5 (41.7)
Non-smoker, n (%)	12 (50)	7 (58.3)
Education			χ² = 2.250	0.522
Can read, n (%)	4 (16.67)	0 (0.00)
Primary, n (%)	5 (20.83)	3 (25.0)
High school, n (%)	10 (41.66)	6 (50.0)
College, n (%)	5 (20.83)	3 (25.0)

Table 1. Socio-Demographic Data of the Case and Control Groups

Cases (n = 24)

Controls (n = 12)

Test of significance

P-value

χ²: Chi-square test. t: independent samples test. P value ≤ 0.05 is considered significant. P value < 0.001 is considered highly significant. SD: standard deviation.

Age (mean ± SD), years

27.54 ± 5.509

28.08 ± 5.418

t = 0.280

0.781

Gender

χ² = 0.00

1.000

Male, n (%)

14 (58.3)

7 (58.3)

Female, n (%)

10 (41.7)

5 (41.7)

Smoking

χ² = 0.223

0.637

Smoker, n (%)

12 (50)

5 (41.7)

Non-smoker, n (%)

12 (50)

7 (58.3)

Education

χ² = 2.250

0.522

Can read, n (%)

4 (16.67)

0 (0.00)

Primary, n (%)

5 (20.83)

3 (25.0)

High school, n (%)

10 (41.66)

6 (50.0)

College, n (%)

5 (20.83)

3 (25.0)

**Table 2.** Studied Patients’ Clinical Criteria
	Mean ± SD	Range (min. - max.)
PANSS: Positive and Negative Syndrome Scale; PANSS P: Positive Scale; PANSS N: Negative Scale; PANSS G: General Psychopathology Scale; SCoRS: Schizophrenia Cognition Rating Scale; SD: standard deviation.
Age at onset of disorder, years	22.58 ± 4.169	16 - 31
Duration of disorder, years	4.96 ± 3.043	1 - 12
Number of episodes	3.29 ± 1.853	1 - 7
PANSS P score	18.96 ± 3.316	13 - 23
PANSS N score	18.75 ± 3.970	12 - 27
PANSS G score	29.25 ± 5.318	20 - 38
SCoRS global rating score	2.63 ± 0.576	2 - 4

Table 2. Studied Patients’ Clinical Criteria

Mean ± SD

Range (min. - max.)

PANSS: Positive and Negative Syndrome Scale; PANSS P: Positive Scale; PANSS N: Negative Scale; PANSS G: General Psychopathology Scale; SCoRS: Schizophrenia Cognition Rating Scale; SD: standard deviation.

Age at onset of disorder, years

22.58 ± 4.169

16 - 31

Duration of disorder, years

4.96 ± 3.043

1 - 12

Number of episodes

3.29 ± 1.853

1 - 7

PANSS P score

18.96 ± 3.316

13 - 23

PANSS N score

18.75 ± 3.970

12 - 27

PANSS G score

29.25 ± 5.318

20 - 38

SCoRS global rating score

2.63 ± 0.576

2 - 4

**Table 3.** Correlation Between Demographic Data, PANSS and SCoRS and the Nociceptive Reflex
	Subjective pain threshold	Nociceptive threshold
Correlation is significant at the 0.05 level (two-tailed). *Correlation is highly significant at the 0.01 level (two-tailed). PANSS: Positive and Negative Syndrome Scale; PANSS P: Positive Scale; PANSS N: Negative Scale; PANSS G: General Psychopathology Scale; SCoRS: Schizophrenia Cognition Rating Scale.
Age	0.377	0.023*	0.456	0.005**
Gender	-0.310	0.066	-0.177	0.301
Smoking	0.035	0.840	0.054	0.755
Education	-0.024	0.890	0.059	0.731
Duration of disorder	0.594	0.002**	0.589	0.002**
Number of psychotic episodes	0.545	0.006**	0.553	0.005**
PANSS P	-0.178	0.406	-0.291	0.168
PANSS N	0.413	0.045*	0.365	0.080
PANSS G	0.403	0.051	0.225	0.291
SCoRS global rating	0.512	0.011*	0.345	0.099

Table 3. Correlation Between Demographic Data, PANSS and SCoRS and the Nociceptive Reflex

Subjective pain threshold

Nociceptive threshold

Correlation coefficient

P value

Correlation coefficient

P value

*Correlation is significant at the 0.05 level (two-tailed). **Correlation is highly significant at the 0.01 level (two-tailed). PANSS: Positive and Negative Syndrome Scale; PANSS P: Positive Scale; PANSS N: Negative Scale; PANSS G: General Psychopathology Scale; SCoRS: Schizophrenia Cognition Rating Scale.

Age

0.377

0.023*

0.456

0.005**

Gender

-0.310

0.066

-0.177

0.301

Smoking

0.035

0.840

0.054

0.755

Education

-0.024

0.890

0.059

0.731

Duration of disorder

0.594

0.002**

0.589

0.002**

Number of psychotic episodes

0.545

0.006**

0.553

0.005**

PANSS P

-0.178

0.406

-0.291

0.168

PANSS N

0.413

0.045*

0.365

0.080

PANSS G

0.403

0.051

0.225

0.291

SCoRS global rating

0.512

0.011*

0.345

0.099

**Table 4.** Effect of Different Treatments on the Subjective Pain Threshold and Nociceptive Threshold
Treatment	No.	Mean ± SD	Test of significance	P value
F: analysis of variance test. Correlation is significant at the 0.05 level (two-tailed). *Correlation is highly significant at the 0.01 level (two-tailed). SD: standard deviation.
Subjective pain threshold			F = 2.516	0.068
Haloperidol	4	40.00 ± 20.06
Risperidone	7	48.00 ± 19.86
Olanzapine	4	37.75 ± 14.24
Clozapine	1	100.00
Aripiprazole	3	39.33 ± 9.23
Amisulpride	5	42.40 ± 13.16
Nociceptive threshold			F = 1.955	0.135
Haloperidol	4	30.0 ± 2.82
Risperidone	7	38.29 ± 11.85
Olanzapine	4	35.0 ± 6.63
Clozapine	1	60.00
Aripiprazole	3	34.00 ± 5.29
Amisulpride	5	35.20 ± 9.65

Table 4. Effect of Different Treatments on the Subjective Pain Threshold and Nociceptive Threshold

Treatment

No.

Mean ± SD

Test of significance

P value

F: analysis of variance test. *Correlation is significant at the 0.05 level (two-tailed). **Correlation is highly significant at the 0.01 level (two-tailed). SD: standard deviation.

Subjective pain threshold

F = 2.516

0.068

Haloperidol

40.00 ± 20.06

Risperidone

48.00 ± 19.86

Olanzapine

37.75 ± 14.24

Clozapine

100.00

Aripiprazole

39.33 ± 9.23

Amisulpride

42.40 ± 13.16

Nociceptive threshold

F = 1.955

0.135

Haloperidol

30.0 ± 2.82

Risperidone

38.29 ± 11.85

Olanzapine

35.0 ± 6.63

Clozapine

60.00

Aripiprazole

34.00 ± 5.29

Amisulpride

35.20 ± 9.65