Kuzeymen Balıkçı

Associations of oxytocin and vasopressin plasma levels with neurocognitive, social cognitive and meta cognitive function in schizophrenia

Many with schizophrenia experiences deficits in social cognition, neurocognition and metacognition. Yet the biological mechanisms which may underpin these cognitive deficits are poorly understood. Two candidate causes of these deficits are disturbances in oxytocin (OT) and vasopressin (VP). To explore this we assessed plasma OT and VP in 34 schizophrenia patients and 31 healthy controls. We also concurrently assessed social cognition using the Reading the Mind from the Eyes test, neurocognition using the Wisconsin Card Sorting Test and metacognition using the Metacognitive Assessment Scale-Abbreviated. Group comparisons revealed lower plasma OT levels in the schizophrenia group. Plasma VP levels did not differ between groups. Correlations revealed that lower levels of OT were associated with poorer levels of metacognitive functioning in the schizophrenia group but not poorer social cognition or neurocognition. In a stepwise multiple regression, plasma OT level, neurocognition and social cognition contributed uniquely to the prediction of metacognition in the schizophrenia group. Results may suggest that disturbance in OT is linked with deficits in metacognition and may interact with other forms of cognitive deficits, interfering with the persons abilities to form a complex and integrated sense of self and others.

The developmental origins of metacognitive deficits in schizophrenia.

The deficits in metacognition have been observed in schizophrenia but developmental roots of impaired metacognition are not well understood. Accordingly, this study compared metacognitive abilities of patients with schizophrenia and healthy group and examined the relationship between childhood trauma, attachment style and caregiver attitudes with metacognitive capacity which might contribute to metacognitive deficits in patient group. 35 patients with schizophrenia and 35 healthy people were included in the study. Metacognitive capacity was measured using the Metacognition Assessment Scale Abbreviated (MAS-A). This scale comprises four domains: self-reflectivity, understanding others mind, decentration and mastery. Group comparisons revealed that schizophrenia patients had greater deficits in metacognitive ability. We found that the report of childhood emotional abuse, a pattern of anxious attachment and over protection by caregivers were uniquely related to metacognitive capacity.

Oxytocin and social cognition in patients with schizophrenia: comparison with healthy siblings and healthy controls

ABSTRACT Objective: There is substantial evidence from animal research indicating a key role of the neuropeptide oxytocin (OT) in the regulation of complex social cognition and behaviour. Social cognition is indispensable for social relationships for the whole of human society, and numerous studies have shown impaired social cognition in schizophrenia (SCH) and unaffected first-degree relatives also seem to be impaired, albeit to a lesser extent. Because of that, this study focuses on the role of OT in social cognition in SCH. Methods: Twenty-seven patients with SCH, 27 healthy siblings (HS) of these patients, and 27 psychologically healthy controls (HC) were included in the study. Blood samples were collected through a peripheral venous catheter. Differences in the socio-demographical and WAIS-R were tested by chi-square and one way-ANOVA. To explore the relationships between social cognition and blood samples we performed Pearson correlations. MANCOVA (gender and WAIS-R as covariates) test was performed to investigate the effect of gender on blood levels of OT and WAIS-R on social cognition. Results: Significant differences were found in neurocognitive and social cognitive capacity but not in OT levels. In the healthy control group, there was a positive correlation between blood OT levels and RMET. There is a statistically significant difference between high and low OT groups with regard to social cognition in all subtests of the RMET. Conclusions: In the current study, we found that patients had deficits in social cognition and neurocognition. Lower endogenous OT levels are also predictive for poor social cognitive functioning in HS and HC.

Reliability and validity of Turkish Form of Somatic Symptom Scale and Level 2 Somatic Symptom Scale

Objective: This study is to demonstrate the reliability and validity of the Turkish form of Somatic Symptom Scale and Level 2 Somatic Symptom Scale developed according to DSM-5 criteria. Methods: This study was carried out with patients with a diagnosis of any somatic symptom disorder according to DSM-5 criteria who are under treatment in Celal Bayar University Faculty of Medicine Psychiatry Inpatient or Outpatient Clinics. Patients with any mental disease according to DSM-5 criteria except for somatic symptom disorders and patients who have physical or neurological disease requiring continuous treatment were excluded. Accordingly, 31 patient with somatic symptom disorder, 16 patients with illness anxiety disorder and three patients with conversion disorder were included. As the healthy control group 100 volunteers without any mental or physical disease were included. Beside Somatic Symp-tom Scale and Level 2 Somatic Symptom Scale, the most widely used self-rated scale, Health Anxiety Inven-tory (HAI) was used for concurrent validity. In reliability analysis internal consistency coefficient and item-total corre-lation analysis; in validity analyses factor analysis and correlation analysis with the Pearson Correlation Analysis (PCA) was performed. ROC analysis was conducted to determine sensitivity and specificity of the scale and area under the curve above 0.90 is considered as statistically significant. Results: The mean age of the study group was 29.0±11.9 years and 61.3% of the sample group (n=92) were female. 63.3% of the group were college graduates, 19.3% primary school graduates, 10.7% is also high school graduates. Disease duration of patient group was 17.4±11.8 years. The internal consistency of the Level 2 Somatic Symptom Scale was 0.83 and, item-total correla-tion coefficients of the Level 2 Somatic Symptom Scale were between 0.26 and 0.62. The internal consistency of the Somatic Symptom Scale was 0.96 and, item-total correlation coefficients of the Somatic Symptom Scale were between 0.89 and 0.92. In the exploratory factor analysis of Level 2 Somatic Symptom Scale, single-factor solution was obtained and the eigenvalue was 4.67, explaining 31.16% of the total variance. Factor loadings of the items were between 0.41 and 0.78. Coefficient of correlation analysis with HAI was calculated as r=0.59. Coefficient of correlation analysis of Somatic Symptom Scale with HAI was calculated as r=0.83. According to ROC analysis, the area under the curve was found as 0.92 for Level 2 Somatic Symptom Scale, and 0.98 for Somatic Symptom Scale. Conclusion: These findings have been shown that the Somatic Symptom Scale and Level 2 Somatic Symptom Scale are reliable and valid for Turkish.

The comparison of executive functions, social cognition and plasma oxytocin level between mothers of schizophrenia patients and healthy control: Searching for a new endophenotype

Objective: Previous studies documented that there were a variety of endophenotypes that helped to diagnose as well as to predict functionality and treatment response. There is little, if any research that focused on investigating biochemical endophenotypes. Besides, the studies that include executive functions and social cognition, which were accepted as endophenotypes, have different results. In studies involving schizophrenia patients, the deficiency of oxytocin was found to be the most important hormone that would affect the treatment process. However, there have been no endophenotype studies that investigated the role of oxytocin hormone in the treatment process of schizophrenia patients. The purpose of the present study was twofold: (a) to detect new endophenotypes, and (b) to test endophenotypes that were previously found by focusing on the schizophrenia patients’ mothers. Methods: The participants were the healthy mothers of schizophrenia patients and healthy control group. They took the Reading the Mind in the Eyes Test, Wisconsin Card Sorting Test, and Wechsler Adult Intelligence Scale vocabulary subtest, respectively. In addition, participants’ blood samples were collected to include the level of plasma oxytocin as a biochemical in the data analyses. Results: Results revealed that there was a significant difference in plasma oxytocin levels for the healthy mothers of schizophrenia patients and the healthy control group. Low level of plasma oxytocin level was found to be the only significant factor that differentiates the patients’ mothers and the healthy control group. When the results of the Reading the Mind in the Eyes Test that measures executive functions, and the Wisconsin Card Sorting Test that measures social cognition were analyzed, no significant differences were found between the groups. Discussion: Our findings showed that oxytocin hormone could be a new endophenotype for schizophrenia. However, there is still a need for studies that focus on the investigation of detecting new endophenotypes.