Deconstructing the genetic architecture of treatment-resistant schizophrenia in East Asian ancestry.

BACKGROUND: Treatment-resistant schizophrenia (TRS) affects a substantial proportion of patients who do not respond adequately to antipsychotic medications, yet the underlying biological mechanism remains poorly understood. This study investigates the link between the genetic predisposition to schizophrenia and TRS. METHODS: 857 individuals diagnosed with schizophrenia were divided into TRS (n = 142) and non-TRS (n = 715) based on well-defined TRS criteria. Polygenic risk scores (PRS) were calculated using schizophrenia genome-wide association summary statistics from East-Asian and European ancestry populations. PRS was estimated using both P-value thresholding and Bayesian framework methods. Logistic regression analyses were performed to differentiate between TRS and non-TRS individuals. RESULTS: The schizophrenia PRS derived from the East-Asian training dataset effectively distinguished between TRS and non-TRS individuals (R2 = 0.029, p = 4.86 ×10-5, pT = 0.1, OR = 1.52, 95% CI = 1.242-1.861), with higher PRS values observed in the TRS group. Similar PRS analysis was conducted based on the European ancestry GWAS summary statistics, but we found superior prediction based on the East-Asian ancestry discovery data. CONCLUSION: This study reveals an association between common risk variants for schizophrenia and TRS status, suggesting that the genetic burden of schizophrenia may partly contribute to treatment resistance in individuals with schizophrenia. These findings propose the potential use of genetic risk factors for early TRS identification and timely access to clozapine. However, the ancestral background of the discovery sample is crucial for successfully implementing PRS in clinical settings.

Esquizofrenia resistente al tratamiento. I, concepto e impacto clínico / Treatment resistant schizophrenia. I, concept and clinical impact

La esquizofrenia es una psicosis crónica que se caracteriza por tres dominios sintomáticos: síntomas positivos, síntomas negativos y síntomas cognitivos. Se estima que afecta al 1 % de la población. El desarrollo de la psicofarmacología y del tratamiento de la esquizofrenia ha permitido distinguir genios evolutivos según la respuesta terapéutica. En este sentido es que se delinea el concepto de esquizofrenia resistente al tratamiento (ERT). Se estima ERT en un 30 % aproximadamente de los sujetos que padecen esquizofrenia. La identificación temprana y adecuada de este subgrupo de individuos se relaciona con una mejor respuesta. Este artículo es una narrativa sobre el concepto de ERT y su impacto clínico.

Schizophrenia is a chronic psychosis characterized by three symptom domains: positive symptoms, negative symptoms and cognitive symptoms. Its prevalence is about 1 % of the general population. The development of psychopharmacology and schizophrenia treatment have made possible the distinction between different clinical courses and outcomes according to treatment response. This is the basis for the concept of treatment resistant schizophrenia (TRS), which can be present in 30 % of schizophrenic patients. Early and adequate identification of this subgroup is related to better outcomes. Authors analyze the previously mentioned concept and its clinical impact.

Expression of BDNF-Associated lncRNAs in Treatment-Resistant Schizophrenia Patients.

Long non-coding RNAs (lncRNAs) play a decisive role in the development of the central nervous system and modulation, differentiation, and function of neurons. Thus, any abnormal pattern of expression of these transcripts might alter normal development leading to neuropsychiatric disorders. In this regard, transcripts of brain-derived neurotrophic factor (BDNF) and four BDNF-associated lncRNAs (BDNF-AS, MIR137HG, MIAT, and PNKY) were evaluated in the peripheral blood of schizophrenia (SCZ) patients as well as normal subjects. The results indicated that the relative expression (RE) of PNKY was higher in SCZ patients as compared with controls (posterior beta of RE = 2.605, P value = 0.006) and in female patients compared with female controls (posterior beta of RE = 2.831, P value < 0.0001). BDNF expression was also higher in SCZ patients when compared with controls (posterior beta of RE = 0.64, P value < 0.036). Finally, a correlation was detected between the disease status and gender in terms of BDNF-AS expression (P value = 0.026). An inverse correlation was also found between levels of PNKY and age in the control group (r = - 0.30, P value < 0.0001). Expressions of BDNF and all lncRNAs were correlated with each other in both patients and controls. PNKY had the best diagnostic power among all assessed genes in the identification of disease status (area under curve = 0.78). BDNF, BDNF-AS, MIR137HG, and MIAT genes could discriminate SCZ patients from normal subjects with diagnostic power of 71%, 72%, 67%, and 68%, respectively. The current investigation suggests the possibility of the application of transcript levels of lncRNAs as an SCZ diagnostic marker. However, it warrants further studies in larger sample sizes.

Neurosurgery for Refractory Schizophrenia: A Systematic Literature Review

Schizophrenia is a chronic and disabling psychiatric disease that can be refractory to conventional treatment. The present study aims to gather information about the circuitry related to schizophrenia to describe possible surgical targets, and to establish whether psychosurgery can be a safe and effective treatment option for refractory schizophrenia. A systematic review of the literature was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. An electronic search was performed in the Pubmed and BVSalud databases using medical subject headings (MeSH) combined with Boolean operators. Out of the 724 studies retrieved, 13 were included in the review. Regarding leucotomy without a stereotactic approach, we found side effects such as irritability, nervous excitement, cases of disinhibition, and compromised normal social control. In other stereotactic procedures, there was some improvement, mainly regarding aggressiveness and positive symptoms; an anterior capsulotomy had an efficacy rate of 74% according to the Clinical Global Impression (CGI) rating scales. The only deep brain stimulation (DBS) case report found in our study described a significant improvement in the positive and negative symptoms. The use of a stereotactic approach enables psychosurgery to be a safe and effective treatment option in cases of refractory schizophrenia, improving the quality of life and the symptoms. Cognitive and negative symptoms remain a challenge in the treatment of schizophrenia, revealing that more targets in the circuitrymust be surgically explored. Furthermore,more clinical trials are needed to compare these many surgical techniques and targets, using a standard evaluation parameter. The results show that DBS has a promising future in the treatment of refractory schizophrenia.