Table 3.

Within-group correlation coefficients for tryptophan metabolites and clinical symptoms for first-episode schizophrenia patients (tests for zero correlation, two-sided)

Clinical symptoms	Tryptophan metabolites
	TRP	5-HT	5-HIAA	MEL	KYN	3-OHKY	TRPA
Baseline (neuroleptic-naive)
BPRS
Total	−0.234	−0.090	−0.306	−0.186	−0.384	−0.618a	−0.369
Psychosis	−0.195	0.049	−0.107	−0.233	−0.283	−0.339	−0.221
Thought disturbance	−0.136	0.184	−0.165	−0.291	−0.308	−0.387	−0.261
Paranoia	−0.094	−0.129	−0.006	0.027	−0.042	−0.088	−0.096
Anxious depression	0.082	−0.204	−0.279	0.136	−0.016	−0.331	−0.076
SAPS – Total	−0.229	−0.143	−0.317	−0.235	−0.276	−0.387	−0.111
SANS – Total	−0.035	−0.019	−0.342	−0.121	−0.163	−0.129	−0.072
4 wk (medicated)
BPRS
Total	0.022	0.164	−0.020	0.044	0.259	0.413	0.163
Psychosis	−0.120	0.070	−0.075	0.052	0.165	0.302	0.100
Thought disturbance	−0.022	0.166	−0.019	0.119	0.220	0.409	0.207
Paranoia	−0.003	0.120	−0.062	0.171	0.245	0.278	0.093
Anxious depression	0.019	−0.086	0.070	−0.079	0.271	0.403	0.189
SAPS – Total	−0.098	0.129	−0.020	−0.063	0.056	0.235	0.110
SANS – Total	0.063	0.175	−0.207	0.118	−0.011	0.060	0.204

TRP, Tryptophan; 5-HT, serotonin ; 5-HIAA, 5-hydroxyindoleacetic acid ; MEL, melatonin; KYN, kynurenine; 3-OHKY, 3-hydroxykynurenine; TRPA, tryptamine; BPRS, Brief Psychiatric Rating Scale ; SAPS, Schedule for the Assessment of Positive Symptoms; SANS, Schedule for the Assessment of Negative Symptoms.

^aDrton–Perlman simultaneous p values, significant at p<0.05 and trend significant at p<0.10.