Patients with first-episode psychosis in northern Taiwan: neurocognitive performance and niacin response profile in comparison with schizophrenia patients of different familial loadings and relationship with clinical features

Table 4 Spearman’s correlation of baseline quantitative measures among patients with first-episode psychosis (N = 80)

Z-scores	CPT undegraded d’ r (P value)	CPT degraded d’ r (P value)	WCST −Perseverative errors^a r (P value)	WCST Categories achieved r (P value)	Niacin response (NR) abnormality Volumetric NR for 0.1 M and 0.01 M r (P value)
Continuous Performance Test (CPT)
Undegraded d’	1.00	-	-	-	-
Degraded d’	0.77 (< 0.001)	1.00	-	-	-
Wisconsin Card Sorting Test (WCST)				-	-
−Perseverative errors^a	0.46 (< 0.001)	0.35 (0.003)	1.00	-	-
Categories achieved	0.52 (< 0.001)	0.42 (< 0.001)	0.85 (< 0.001)	1.00	-
Niacin response (NR) abnormality					-
Volumetric NR for 0.1 M and 0.01 M	−0.01 (0.94)	0.03 (0.82)	0.01 (0.94)	0.13 (0.31)	1.00 (1.00)

^aTransformed to a negative value to let a more negative Z-score represent a greater impairment compared to the comparison group and hence denoted as − perseverative errors
Abbreviations: CPT = Continuous Performance Test; WCST = Wisconsin Card Sorting Test; NR = niacin response

ISSN: 1471-244X