The relationship between oxytocin, vasopressin and atrial natriuretic peptide levels and cognitive functions in patients with schizophrenia

Figures & data

Table 1. Sociodemographic and clinical characteristics of the patient and control groups in the study.

		Patient group		Control group		P
Sociodemographic Characteristics (n = 123)		N	%	n	%
Sex	Male Female	35 28	55.6 44.4	24 36	40.0 60.0	.084
Age	18–29 30–39 40–49 50–65	10 21 18 14	15.9 33.3 28.6 22.2	9 22 13 16	15.0 36.7 21.7 26.7	.815
Education (year)	0–5 6–8 9–12 >12	17 13 25 8	27.0 20.6 39.7 12.7	19 9 18 14	31.7 15.0 30.0 23.3	.315
Total		63	100.0	60	100.0
Clinical features of schizophrenia patients (n = 63)
Clinical features	Median	Mean	SD	MV	HV
Duration of illness	15	14.13	9.31	1	32
Number of hospitalizations	2	2.71	2.98	0	15
Chlorpromazine Equivalent dose	800	876.19	370.14	200	2200
PANSS Positive	12	12.10	3.03	8	22
PANSS Negative	12	12.22	3.19	7	21
PANSS General	25	26.06	9.33	18	92
PANSS Total	50	50.38	11.74	35	122
CGI	3	3.46	0.62	2	5
GAF	55	53.10	8.10	30	70

Note: SD: standard deviation, EKD: minimum value, EBD: highest value, PANSS: Positive and Negative Symptom Scale, CGI: clinical global impression, GAF: general assessment of functionality.

Figure 1. Levels of oxytocin, vasopressin and atrial natriuretic peptide.

Table 2. Relationship of neurocognitive test scores with blood hormone levels.

Neurocognitive tests	Patient group (n = 63)			Control group (n = 60)
	Oxytocin	Vasopressin	ANP	Oxytocin	Vasopressin	ANP
Stroop 1 (word reading)	0.123	−0.174	0.143	−0.165	0 . 347**	0.062	r
	0.336	0.172	0.264	0.209	0 . 007	0.639	p
Stroop 2 (colour reading)	0.044	−0.109	0.198	−0.090	0.215	0.046	r
	0.735	0.396	0.119	0.495	0.099	0.725	p
Stroop difference	0.041	−0.068	0.163	−0.021	0.047	0.017	r
	0.751	0.598	0.203	0.874	0.721	0.896	p
Word reading correction	0.013	0.000	−0.041	−0 . 301*	0.001	0.011	r
	0.922	0.999	0.750	0 . 019	0.993	0.932	p
Word reading mistake	−0.088	0.031	0.145	−0.189	−0.003	−0.015	r
	0.493	0.812	0.256	0.149	0.984	0.911	p
Colour reading correction	0.119	−0.116	0.048	−0 . 281*	0.182	0.041	r
	0.352	0.367	0.707	0 . 030	0.163	0.753	p
Colour reading mistake	0.089	−0.051	0.087	−0.087	0.014	0.080	r
	0.490	0.693	0.496	0.507	0.916	0.545	p
TMT-A completing duration	0.012	−0.066	0.111	−0 . 314*	0.058	−0.092	r
	0.925	0.605	0.385	0 . 015	0.660	0.484	p
TMT-B completing duration	0.177	−0.053	0 . 268*	−0.216	0.130	−0.071	r
	0.193	0.701	0 . 046	0.097	0.321	0.591	p
Visual instant memory score (WMS)	−0.173	0.130	−0.162	0.314*	−0.211	0.201	r
	0.176	0.309	0.205	0.015	0.106	0.123	p
Instant memory score (VLT)	−0.219	0.173	−0.180	0.169	−0 . 269*	0.142	r
	0.085	0.176	0.158	.196	0.038	0.280	p
Total learning score (VLT)	−0.071	0.019	−0.235	0.190	−0.189	0.119	r
	0.578	0.883	0.063	0.146	0.149	0.363	p
Highest learning score (VLT)	−0.023	−0.050	−0.246	0.159	−0.064	0.233	r
	0.858	0.698	0.052	0.226	0.630	0.073	p
Long-term memory score (VLT)	−0.082	−0.022	−0.321*	0.179	−0.104	0.043	r
	0.523	0.863	0.010	0.170	0.427	0.746	p

Note: * p < .05, **p < .001; r: Pearson correlation ratio; VLT: Verbal learning Test; TMT: Trail Making Test; WMS: Weschler Memory Scale. The significance for bold values is p values under 0.05.

Table 3. Comparison of correlations between neurocognitive tests and oxytocin, vazopressin and ANP level in patient and healthy controls.

Neurocognitive tests	Oxytocin		Vasopressin		ANP
	p	CI	p	CI	p	CI
Stroop 1 (word reading)	.117	−0.0723 0.6231	.004	−0.8295 −0.1702	.658	−0.2730 0.4288
Stroop 2 (colour reading)	.468	−0.2251 0.4811	.076	−0.6550 0.0351	.403	−0.2021 0.4944
Stroop difference	.737	−0.2952 0.4137	.534	−0.4636 0.2437	.425	−0.2104 0.4906
Word reading correction	.080	−0.0385 0.6411	.996	−0.3557 0.3538	.779	−0.4042 0.3047
Word reading mistake	.577	−0.2512 0.4442	.854	−0.3221 0.3872	.384	−0.1981 0.5047
Colour reading correction	.027	0.0440 0.7224	.104	−0.6320 0.0620	.969	−0.3473 0.3610
Colour reading mistake	.219	−0.1045 0.4469	.725	−0.4165 0.2921	.969	−0.3456 0.3595
TMT-A complating duration	.069	−0.0256 0.6515	.502	−0.4720 0.2350	.271	−0.1572 0.5454
TMT-B completing duration	.031	0.0344 0.7179	.320	−0.5263 0.1766	.062	−0.0172 0.6678
Visual instant memory score (WMS)	.007	−0.8001 −0.1336	.062	−0.0183 0.6707	.047	−0.6909 −0.0037
Instant memory score (VLT)	.035	−0.7136 −0.0293	.015	0.0857 0.7610	.079	−0.6542 0.0380
Total learning score (VLT)	.154	−0.5975 0.0983	.256	−0.1499 0.5476	.052	−0.6826 0.0043
Highest learning score (VLT)	.322	−0.5244 0.1765	.939	−0.3405 0.3669	.008	−0.7945 −0.1232
Long-term memory score (VLT)	.155	−0.5978 0.0987	.656	−0.2747 0.4311	.042	−0.6884 −0.0119

Note: VLT: Verbal learning Test; TMT: Trail Making Test; WMS: Weschler Memory Scale Cl: Confidence interval.

Table 4. The relationship between oxytocin, vasopressin and atrial natriuretic peptide levels and responses to facial expressions in the facial expression test in the patient and healthy group.

Neurocognitive tests	Patient group (n = 63)			Control group (n = 60)
	Oxytocin	Vasopressin	ANP	Oxytocin	Vasopressin	ANP
Responding time for happy expression	0.287*	−0.234	0.195	−0.496**	0.264*	−0.282*	r
	0.023	0.065	0.126	0.000	0.042	0.029	p
Responding time for sad expression	0.332**	−0.208	0.211	−0.422**	0.127	−0.305*	r
	0.008	0.102	0.097	0.001	0.334	0.018	p
Responding time for angry expression	0.221	−0.198	0.047	−0.375**	0.172	−0.218	r
	0.082	0.120	0.716	0.003	0.189	0.095	p
Responding time for surprised expression	0.235	−0.181	0.143	−0.450**	0.178	−0.160	r
	0.064	0.157	0.263	0.000	0.173	0.222	p
Responding time for frightened expression	0.241	−0.223	0.104	−0.505**	−0.079	−0.217	r
	0.057	0.079	0.418	0.000	0.550	0.096	p
Responding time for disgusted expression	0.259*	−0.184	0.195	−0.409**	0.100	−0.142	r
	0.040	0.149	0.125	0.001	0.449	0.280	p
Responding time for neutral expression	0.332**	−0.188	0.245	−0.403**	0.363**	−0.182	r
	0.008	0.139	0.053	0.001	0.004	0.163	p
Total responding time for expressions	0.292*	−0.16	0.171	−0.530**	0.191	−0.263*	r
	0.020	0.089	0.181	0.000	0.143	0.043	p
Correct number of happy expression	−0.024	0.178	−0.018	0.076	0.038	0.191	r
	0.851	0.163	0.888	0.562	0.775	0.145	p
Correct number for sad expression	0.089	0.159	−0.025	0.353**	−0.113	−0.036	r
	0.486	0.213	0.849	0.006	0.389	0.785	p
Correct number for angry expression	0.036	0.084	0.157	0.413**	−0.125	0.015	r
	0.780	0.515	0.220	0.001	0.340	0.907	p
Correct number for surprised expression	0.112	0.001	0.005	0.242	−0.180	−0.045	r
	0.382	0.994	0.968	0.062	0.168	0.731	p
Correct number for frightened expression	0.217	−0.098	0.054	0.305*	0.128	0.251	r
	0.087	0.446	0.672	0.018	0.328	0.053	p
Correct number for disgusted expression	0.086	0.003	−0.072	0.175	0.007	−0.011	r
	0.503	0.979	0.573	0.182	0.956	0.932	p
Correct number for neutral expression	−0.111	0.232	−0.152	−0.164	−0.036	−0.100	r
	0.386	0.067	0.234	0.210	0.785	0.449	p
Total correct number of expressions	0.093	0.102	−0.025	0.357**	−0.047	0.081	r
	0.469	0.425	0.844	0.005	0.719	0.536	p

* p < .05, **p < .001. Note: The significance for bold values is p values under 0.05.

Table 5. Comparison correlations between facial emotion recognition test and oxytocin, vazopressin and ANP in patient and healthy controls.

	Oxytocin		Vasopressin		ANP
	p	CI	p	CI	p	CI
Happy expression	<.001	0.4545 1.0550	.006	−0.8111 −0.1431	.008	0.1219 0.7921
Sad expression	<.001	0.4188 1.0315	.067	−0.6657 0.0243	.004	0.1628 0.8263
Angry expression	.001	0.2491 0.8954	.043	−0.6975 −0.0108	.147	−0.0929 0.6000
Surprised expression	.001	0.3473 0.9713	.049	−0.6876 0.0005	.099	−0.0573 0.6369
Frightened expression	<.001	0.4163 1.0228	.425	−0.4847 0.2071	.079	−0.0380 0.6522
Disgusted expression	<.001	0.3264 0.9576	.121	−0.6194 0.0758	.066	−0.0226 0.6677
Neutral expression	<.001	0.3976 1.0156	.002	−0.8558 −0.2020	.019	0.0696 0.7484
Total responding time for expressions	<.001	0.4992 1.0876	.026	−0.7306 −0.0487	.017	0.0773 0.7539
Correct number of happy expression	.588	−0.4492 0.2582	.443	−0.2151 0.4840	.253	−0.5485 0.1488
Correct number for sad expression	.131	−0.5877 0.0787	.139	−0.0883 0.6087	.953	−0.3441 0.3649
Correct number for angry expression	.029	−0.6911 −0.0371	.257	−0.1512 0.5507	.439	−0.2146 0.4870
Correct number for surprised expression	.467	−0.4677 0.2186	.323	−0.1764 0.5224	.787	−0.3067 0.4021
Correct number for frightened expression	.609	−0.4166 0.2474	.219	−0.5665 0.1344	.274	−0.5327 0.1551
Correct number for disgusted expression	.624	−0.4335 0.2636	.983	−0.3586 0.3510	.741	−0.4124 0.2955
Correct number for neutral expression	.770	−0.2980 0.3988	.141	−0.0889 0.6031	.775	−0.3998 0.2992
Total correct number of expressions	.129	−0.5872 0.0781	.419	−0.2102 0.4952	<.001	−1.0915 −0.5627

Note: CI: Confidence interval. The significance for bold values is p values under 0.05.

Table 6. Correlation of neuropsychiatric variables and neuropeptides obtained by principal component analysis.

		Patient group (n = 63)			Control group (n = 60)
		Oxytocin	Vasopressin	ANP	Oxyitocin	Vasopressin	ANP
Total responding time for expressions	r p	0.292 0.020	−0.216 0.089	0.171 0.181	−0.530 <0.001	0.191 0.143	−0.263 0.043
Total correct number of expressions	r p	0.093 0.469	0.102 0.425	−0.025 0.844	0.357 0.005	−0.047 0.719	0.081 0.536
Correct number for frightened expression	r p	0.217 0.087	−0.098 0.446	0.054 0.672	0.305 0.018	0.128 0.328	0.251 0.053
Correct number for disgusted expression	r p	0.086 0.503	0.003 0.979	−0.072 0.573	0.175 0.182	0.007 0.956	−0.011 0.932
Stroop-difference	r p	0.041 0.751	−0.068 0.598	0.163 0.203	−0.021 0.874	0.047 0.721	0.017 0.896
Stroop 1 (word reading)	r p	0.123 0.336	−0.174 0.172	0.143 0.264	−0.165 0.209	0.347 0.007	0.062 0.639
Total learning score (VLT)	r p	−0.071 0.578	0.019 0.883	−0.235 0.063	0.190 0.146	−0.189 0.149	0.119 0.363
Highest learning score (VLT)		−0.023 0.858	−0.050 0.698	−0.246 0.063	0.159 0.226	−0.064 0.630	0.233 0.073

Note: The significance for bold values is p values under 0.05.