Decreased Plasma Levels of Kynurenine and Kynurenic Acid in Previously Treated and First-Episode Antipsychotic-Naive Schizophrenia Patients.

Tryptophan (TRP) catabolites exert neuroactive effects, with the plethora of evidence suggesting that kynurenic acid (KYNA), a catabolite of the kynurenine pathway (KP), acts as the regulator of glutamate and acetylcholine in the brain, contributing to the schizophrenia pathophysiology. Newer evidence regarding measures of KP metabolites in the blood of schizophrenia patients and from the central nervous system suggest that blood levels of these metabolites by no means could reflect pathological changes of TRP degradation in the brain. The aim of this study was to investigate plasma concentrations of TRP, kynurenine (KYN) and KYNA at the acute phase and remission of schizophrenia in a prospective, case-control study of highly selected and matched schizophrenia patients and healthy individuals. Our study revealed significantly decreased KYN and KYNA in schizophrenia patients (p < 0.001), irrespective of illness state, type of antipsychotic treatment, number of episodes or illness duration and no differences in the KYN/TRP ratio between schizophrenia patients and healthy individuals. These findings could be interpreted as indices that kynurenine pathway might not be dysregulated in the periphery and that other factors contribute to observed disturbances in concentrations, but as our study had certain limitations, we cannot draw definite conclusions. Further studies, especially those exploring other body compartments that participate in kynurenine pathway, are needed.

Cross-Cultural Adaptation and Validation of the Serbian Version of the Brief Assessment of Cognition in Schizophrenia Scale.

The Brief Assessment of Cognition in Schizophrenia (BACS) scale was developed for the assessment of cognitive function in patients with schizophrenia. The objective of this study was to cross-culturally adapt and validate the BACS in to the Serbian language. The study was conducted at the Laza Lazarevic Clinic for Mental Disorders and the Clinic for Psychiatry of the University Clinical Center of Serbia from March 2021 to January 2022. The study enrolled 61 inpatients diagnosed with schizophrenia and 61 healthy controls matched for age and sex. Compared with the healthy control group, the schizophrenia patient group had worse cognitive function in all dimensions measured using BACS (p < 0.001 for all measures). The mean standardized composite BACS score was z = -2.46, and symbol coding (z = -2.54) was the most deficient function. Principal component analysis suggests a two-factor structure, where the first factor consisted of loading the measures of verbal and working memory, attention, speed of information processing, and executive function, while the second factor regarded the loading of motor speed. Cronbach's alpha coefficient demonstrated an excellent level of internal consistency (0.798). These outcomes suggest that the Serbian BACS neurocognitive battery's psychometric properties are satisfactory, with good overall discriminant validity and high internal consistency. The Serbian BACS appears to be a quick and reliable neuropsychological instrument for evaluating global cognition in schizophrenia patients in Serbia.

Patterns of drug prescribing in inpatients with first episode of schizophrenia spectrum disorder: The role of guidelines
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OBJECTIVE: The great discrepancy between clinical guidelines and the routine psychiatric practice in the treatment of schizophrenia is a subject of intensive research, with the aim to promote the rational prescribing of antipsychotics. The aim of this study was to analyze the pattern of drug prescribing in the treatment of inpatients with the first episode of schizophrenia spectrum disorders and the impact of the implementation of the Serbian National Guideline for the Diagnosis and Treatment of Schizophrenia. MATERIALS AND METHODS: This cross-sectional study was conducted at the Clinic for Mental Disorders "Dr Laza Lazarevic" in Belgrade and included a consecutive sample of 675 previously drug-naïve patients with the first episode of schizophrenia spectrum disorders. The data were obtained from the patients' medical records. The analysis of therapy prescribed at discharge included antipsychotics and non-antipsychotic adjuvant therapy. Descriptive statistical methods and methods for testing statistical hypotheses were used to analyze the primary data. RESULTS: The prescribing of second-generation antipsychotics has increased both within antipsychotic monotherapy and within antipsychotic polypharmacy during the period of the study. The use of adjuvant non-antipsychotic pharmacotherapy was very common, but use of benzodiazepines, carbamazepine, and anticholinergic drugs significantly decreased. Long-acting forms of antipsychotics have been rarely used (9.3%). Clozapine was in general underprescribed (10.4%). CONCLUSION: The National Guideline for the Diagnosis and Treatment of Schizophrenia most likely contributed to some positive changes in prescribing patterns during the treatment of the first psychotic episode in daily clinical practice in Serbia. However, antipsychotic polypharmacy and irrational use of adjuvant therapy was still prevalent.