Similarities in cognitive impairment between recent- onset and chronic schizophrenia patients: a consideration for the neurodevelopmental hypothesis.

Impairment in attention, memory, processing speed and executive functions have been described in patients with schizophrenia. Such impairments can be observed in early stages of the disease and in chronic patients; discrepancy in findings regarding the cognitive deficits at different stages of the illness keeps the debate about schizophrenia as a neurodegenerative condition which courses with continuous deterioration, or if deficits remain stable, as the neurodevelopmental hypothesis suggests.

Similitudes en el deterioro cognitivo de pacientes con esquizofrenia de inicio reciente y pacientes crónicos: una consideración sobre la hipótesisdel neurodesarrollo / Similarities in cognitive impairment between recent-onset and chronic schizophrenia patients: a consideration for the neurodevelopmental hypothesis

Se ha descrito la presencia de déficits cognitivos en pacientes con esquizofrenia, dichas alteraciones pueden observarse en fases tempranas y crónicas de la enfermedad.Sin embargo, los hallazgos respecto a los déficits en estas fases aún mantienen el debate sobre si la esquizofrenia es una condición neurodegenerativa que cursa con un deterioro continuo o si los déficits permanecen estables, como sugiere la hipótesis del neurodesarrollo. En el presente estudio se compara el rendimiento cognitivo de pacientes con esquizofrenia de inicio reciente (RO) y pacientes crónicos (CH) con la finalidad de contrastar la hipótesis del neurodesarrollo con la perspectiva neurodegenerativa. Método. Se incluyeron 20 participantes de RO (< 5 años desde el primer episodio psicótico) y 30 pacientes de CH (>5 años desde el primer episodio psicótico). Para la evaluación cognitiva se utilizó la Batería Cognitiva Consensuada MATRICS (MCCB), la Prueba Torre de Londres, la Prueba de Clasificación de Tarjetas de Wisconsin y la Prueba de Stroop. Se utilizó ANCOVA para las comparaciones de grupos. Resultados. No hubo diferencias entre los grupos en la mayoría de las pruebas cognitivas. Se observó una diferencia significativa en la prueba de span espacial del MCCB. Conclusiones. Los déficits cognitivos permanecen estables a lo largo del tiempo; nuestros hallazgos son consistentes con la hipótesis del neurodesarrollo de la esquizofreniamás que con el enfoque neurodegenerativo. (AU)

Impairment in attention, memory, processing speed and executive functions have been described in patients with schizophrenia. Such impairments can be observed in early stages of the disease and in chronic patients; discrepancy in findings regarding the cognitive deficits at different stages of the illness keeps the debate about schizophrenia as a neurodegenerative condition which courses with continuous deterioration, or if deficits remain stable, as the neurodevelopmental hypothesis suggests. The aim of the present study was to compare the cognitive performance of recent-onset (RO) and chronic (CH) schizophrenia patients to contrast the neurodevelopmental hypothesis against the neurodegenerative approach. Methods. Twenty RO participants (< 5 years from first psychotic episode) and 30 CH patients (> 5 years from first psychotic episode) were included in the sample. The MATRICS Consensus Cognitive Battery (MCCB), Tower of London test (ToL), Wisconsin Card Sorting Test (WCST) and Stroop Test were used for cognitive evaluation. ANCOVA analysis was performed for group comparisons. Results. No differences between RO and CH patients were identified on most cognitive tests. However, a significant difference was observed in the visual spatial span test from MCCB. Conclusions. We conclude that cognitive deficits remain stable over the course of the disease. Our findings are consistent with the neurodevelopmental hypothesis of schizophrenia rather than the neurodegenerative approach. (AU)

Immunohistochemical analysis of caspase expression in the brains of individuals with obesity or overweight.

Mechanisms underlying the negative effects of obesity on the brain are still unknown. Obesity is associated with oxidative stress in the brain and neuroinflammation that promotes neurodegenerative diseases. Chronic low-grade neuroinflammation in obesity could be associated with lower volumes of gray matter and lower neuronal density. If neuroinflammation mediated by the expression of cytokines and chemokines leads to apoptosis, this can be assessed by examining caspase expression. The aim of this study was to compare the expression of caspases in the 16 brains of donors with obesity/overweight (n = 8; Body Mass Index [BMI] = 31.6 ± 4.35 kg/m2; 2 females; Age = 52.9 ± 4.76 years) and normal weight (n = 8; BMI = 21.8 ± 1.5 kg/m2; 3 females; Age = 37.8 ± 19.2 years). Sixteen human brain samples were processed. Serial paraffin sections were examined by anti-caspase immunochemistry (caspase-3, caspase-4, caspase-6, caspase-1, caspase-8, and caspase-9 antibodies). Postmortem samples of cerebral cortex tissue were captured as photomicrographs and the images obtained were analyzed using ImageJ software to obtain the percentage of positive caspase expression. Nonparametric Mann-Whitney U tests were performed to compare caspase expression between samples from donors with obesity/overweight and normal weight. Taking into consideration the immunohistochemistry results, the Search Tool for the Retrieval of Interacting Genes was used to model molecular interactions. Results showed that brain samples from individuals with obesity/overweight exhibited significantly greater values of positive expression for Caspase-1 (U = 16.5, p = 0.05, Cohen d = 0.89) and -8 (U = 15, p = 0.03, Cohen d = 0.99) than those from donors with normal weight. This study contributes to the knowledge about the inflammatory effects of obesity/overweight on brain, suggesting the activation of the alternative inflammasome pathway in which interact caspase-1 and -8.

Understanding the relationship between apathy, cognition and functional outcome in schizophrenia: The significance of an ecological assessment.

In recent years there has been an increasing interest in understanding the role apathy plays in mediating the relationship between cognitive impairment and functional outcome. In general, most studies measure cognition with traditional cognitive tests that give explicit instructions and guide the participants toward generating a response. However, given that apathy is defined by a decrease in self-initiated behavior, it is crucial to evaluate cognition with ecological tasks that do not explicitly direct the patient´s motivation to generate behaviors to assess the actual effect. This study investigated whether an ecological cognitive assessment (the Jansari Executive Function Assessment, JEF©) would uniquely contribute to the relationship between cognition, apathy, and functional outcome in schizophrenia. The Apathy Evaluation Scale (AES), neuropsychological tests and the JEF© were administered to 20 patients with schizophrenia. Hierarchical multiple regression and mediation analysis were performed to test the associations between the variables of interest. Results showed that JEF© explained a significant portion of the variance in AES (25%). In addition, apathy explained 36% of the variance in functional outcome. However, AES did not mediate between cognition and functional outcome. Our results highlight the importance of assessing cognition with tasks that require integration of cognitive functions needed for real life demands.

Structural Brain Changes Associated with Overweight and Obesity.

Obesity is a global health problem with a broad set of comorbidities, such as malnutrition, metabolic syndrome, diabetes, systemic hypertension, heart failure, and kidney failure. This review describes recent findings of neuroimaging and two studies of cell density regarding the roles of overnutrition-induced hypothalamic inflammation in neurodegeneration. These studies provided consistent evidence of smaller cortical thickness or reduction in the gray matter volume in people with overweight and obesity; however, the investigated brain regions varied across the studies. In general, bilateral frontal and temporal areas, basal nuclei, and cerebellum are more commonly involved. Mechanisms of volume reduction are unknown, and neuroinflammation caused by obesity is likely to induce neuronal loss. Adipocytes, macrophages of the adipose tissue, and gut dysbiosis in overweight and obese individuals result in the secretion of the cytokines and chemokines that cross the blood-brain barrier and may stimulate microglia, which in turn also release proinflammatory cytokines. This leads to chronic low-grade neuroinflammation and may be an important factor for apoptotic signaling and neuronal death. Additionally, significant microangiopathy observed in rat models may be another important mechanism of induction of apoptosis. Neuroinflammation in neurodegenerative diseases (such as Alzheimer's and Parkinson's diseases) may be similar to that in metabolic diseases induced by malnutrition. Poor cognitive performance, mainly in executive functions, in individuals with obesity is also discussed. This review highlights the neuroinflammatory and neurodegenerative mechanisms linked to obesity and emphasizes the importance of developing effective prevention and treatment intervention strategies for overweight and obese individuals.

Impairment of novelty-related theta oscillations and P3a in never medicated first-episode psychosis patients.

We explored the neurophysiological activity underlying auditory novelty detection in antipsychotic-naive patients with a first episode of psychosis (FEP). Fifteen patients with a non-affective FEP and 13 healthy controls underwent an active involuntary attention task along with an EEG acquisition. Time-frequency representations of power, phase locking, and fronto-parietal connectivity were calculated. The P3a event-related potential was extracted as well. Compared to controls, the FEP group showed reduced theta phase-locking and fronto-parietal connectivity evoked by deviant stimuli. Also, the P3a amplitude was significantly reduced. Moreover, reduced theta connectivity was associated with more severe negative symptoms within the FEP group. Reduced activity (phase-locking and connectivity) of novelty-related theta oscillations, along with P3a reduction, may represent a failure to synchronize large-scale neural populations closely related to fronto-parietal attentional networks, and might be explored as a potential biomarker of disease severity in patients with emerging psychosis, given its association with negative symptoms.

Neurocognition in Bipolar and Depressive Schizoaffective Disorder: A Comparison with Schizophrenia.

INTRODUCTION: Schizoaffective disorder (SA) is classified into bipolar (bSA) and depressive (dSA) subtypes. Although clinical differences between both have been reported, there is no clear information regarding their specific cognitive profile. OBJECTIVE: To compare neurocognition between SA subtypes and schizophrenia (SC). METHODS: A total of 61 patients were assessed and divided into 3 groups: 35 SC, 16 bSA, and 10 dSA. All participants signed an informed consent letter. The MATRICS Consensus Cognitive Battery, Central and South American version was used to assess neurocognition. The study was performed at the Instituto Nacional de Psiquiatría "Ramón de la Fuente". Participants were identified by specialized psychiatrists. Trained neuropsychologists carried out the clinical and cognitive assessment, which lasted 2 h approximately. RESULTS: The cognitive assessment showed a significant difference in Trail Making Test part A subtest (F[2,58] = 4.043; p = 0.023]. Post hoc analyses indicated that dSA obtained a significantly higher score than SC (MD = -11.523; p = 0.018). The f test showed a large effect size (f = 0.401). No statistical differences were observed regarding other cognitive variables. CONCLUSIONS: The cognitive profile of SA subtypes and SC is similar since no differences were found in most subtests. However, dSA may be less impaired than SC in measures of processing speed. Further research with larger samples must be conducted.

Cognitive Reserve and Executive Functions in Adults with Type 2 Diabetes.

BACKGROUND: Adults with type two diabetes mellitus (DM2) show cognitive deficits within the executive function domain. The detrimental effects of DM2 over executive function (EF) performance may be mediated by factors such as cognitive reserve (CR). CR mediates cognitive performance by delaying the appearance of clinical symptoms from subjacent brain pathology or attenuating the severity of such symptoms. Our main goal was to study the effects of CR on executive functions of adults with DM2. METHODS: Data from a total of 1,034 adults were included (362 women, 672 men). Subjects were categorized into four groups: subjects with DM2 and high CR (n = 235), control subjects with high CR (n = 265), subjects with DM2 and low CR (n = 298), and control subjects with low CR (n = 236). CR was quantified through 3 proxies: education, occupational complexity, and leisure activities. Executive functions were evaluated through visual scanning, verbal fluency, and backwards counting tasks. First, a series of four one-way ANOVAs was performed where group was included as a between-subject factor and executive function as a dependent variable. Second, a hierarchical multiple regression analysis was conducted to assess the weight of each CR proxy on EF performance. RESULTS: CR level significantly affected all executive function scores independently of the diabetes status. Hierarchical regression analyses indicated that years of education accounted for most of the variance in the model for executive function performance. In this study, we found that there is a significant effect of CR on executive function performance of DM2 subjects and education is the most important CR proxy.

Association between prolactin serum levels and cognitive function in chronic schizophrenia patients / Asociación de los niveles de prolactina con el funcionamiento cognitivo en pacientes con esquizofrenia crónic

Abstract Introduction Several studies have explored the relationship between serum prolactin levels, symptomatology, and cognitive dysfunction in individuals at high risk for psychosis and patients with a first psychotic episode. However, the relationship between such variables is poorly understood in the case of chronic patients. Objective To assess the relationship between prolactin levels, neuropsychological impairment, and symptom severity in patients with chronic schizophrenia. Method A total of 31 patients with diagnosis of schizophrenia were evaluated between May and December 2018. The age range was 18 to 60 years, with patients receiving antipsychotic treatment during a month at least. Data was obtained from clinical records, interviews, clinimetry, and with the application of the PANSS and the MCCB battery. For the prolactin measurement, the analysis was performed on a sample of 500 microliters of serum, with a chemiluminescence technique. Results The sample was comprised mostly by men (77.4%), with a mean age of 37.65 years, 13.29 years of formal education, and disease duration of 11.58 years. No correlations were observed between prolactin levels and PANSS components and subscales. Only in male patients is there a negative correlation was found between prolactin levels with the overall combined score of the MCCB battery and cognitive domains of reasoning and verbal learning. Discussion and conclusions Men diagnosed with schizophrenia may be particularly vulnerable to the negative effects of hyperprolactinemia on cognition. These preliminary data have clinical implications for close monitoring of prolactin and cognitive decline in males with schizophrenia. Theoretically, these data are suggestive of a protective effect of hormones in women with this condition.

Resumen Introducción Diversos estudios han explorado la relación entre los niveles de prolactina sérica, la sintomatología y la disfunción cognitiva en individuos con alto riesgo de psicosis y pacientes con un primer episodio psicótico. Sin embargo, la relación entre tales variables es poco comprendida en el caso de los pacientes crónicos con esquizofrenia. Objetivo Evaluar la relación entre los niveles de prolactina, el deterioro neuropsicológico y la severidad de los síntomas en pacientes crónicos. Método Se evaluó un total de 31 pacientes. El rango de edad fue de 18 a 60 años, quienes recibieron tratamiento antipsicótico durante un mes como mínimo. Los datos se obtuvieron de entrevistas y de la aplicación de la PANSS y la MCCB. La medición de la prolactina se realizó con una muestra de 500 microlitros de suero, con una técnica de quimioluminiscencia. Resultados La muestra estuvo compuesta en su mayoría por hombres (77.4%), con una edad media de 37.65 años, 13.29 años de escolaridad y una duración de la enfermedad de 11.58 años. No se observaron correlaciones entre los niveles de prolactina y los componentes y subescalas del PANSS. Sólo en los pacientes varones se da una correlación negativa entre los niveles de prolactina con la puntuación global combinada de la batería de MCCB y los dominios cognitivos de razonamiento y aprendizaje verbal. Discusión y conclusiones Los hombres diagnosticados con esquizofrenia pueden ser particularmente vulnerables a los efectos negativos de la hiperprolactinemia sobre la cognición. Teóricamente, estos datos sugieren un efecto protector de las hormonas en las mujeres con esta enfermedad.

Processing speed differences between schizophrenia and schizoaffective disorder: A pilot study.

We aimed to compare processing speed (PS) and its subcomponents in schizophrenia (SC) and schizoaffective disorder (SA). Thirty-five patients were divided into two groups (SC=18; SA=17). PS tasks from the MATRICS Consensus Cognitive Battery Central/South America version were used. Additional PS subcomponents were analyzed (i.e., behavioral execution, response processing, and accuracy). SA obtained significant higher scores than SC in response processing, verbal fluency and the PS general domain. Our results indicate that PS is a potential cognitive marker to differentiate between SC and SA. Further research with larger samples must be conducted.

Principales efectos de la reserva cognitiva sobre diversas enfermedades: una revisión sistemática / Main effects of cognitive reserve on different disorders: A systematic review

Introducción: Se considera la reserva cognitiva (RC) como la optimización de los recursos cerebrales al emplear redes neuronales y estrategias cognitivas alternativas. Se piensa que la RC es una explicación plausible a un mecanismo potencial que permite al cerebro compensar deficiencias, ya sean causadas por el deterioro cerebral o por el declive funcional. Objetivo: Analizar la información de la literatura científica acerca de los efectos de la RC sobre variables clínicas y cognitivas en pacientes con diversas enfermedades distintas a las demencias. Desarrollo: Se realizó una búsqueda sistemática en las bases PubMed/Medline y ScienceDirect de artículos que evaluaran la influencia de la RC sobre variables clínicas y cognitivas en pacientes con enfermedades distintas a las demencias, incluyendo estudios empíricos con diseño longitudinal/transversal y observacional/cuasiexperimental. Se incluyeron 107 artículos. Resultados: Mayores niveles de RC se relacionan con un menor deterioro cognitivo en una gran variedad de trastornos y con una mejor recuperación en pacientes con enfermedad neurológica, psiquiátrica, infecciosa, cáncer, etc. También hay evidencia sobre el papel de la RC como factor protector para el retraso en el desarrollo de enfermedades neurológicas, neuropsiquiátricas, infecciosas, etc. Limitaciones: Podría existir más bibliografía, pues solo exploramos 2 bases. Conclusión: Una aproximación a la RC podría estar constituida por un conjunto de variables (cognitivas, demográficas, físicas, etc.) que parecen influir de manera importante sobre aspectos cognitivos, clínicos y funcionales de diversas enfermedades. Se subraya la necesidad de investigar a profundidad el papel de la RC en el proceso de recuperación y como factor protector en diferentes dolencias

Introduction: Cognitive reserve (CR) is considered as an optimisation of brain resources by using alternative neural networks and cognitive strategies. It is suggested that CR is a plausible explanation of a potential mechanism that allows the brain to compensate deficiencies caused either by brain damage or functional decline. Objective: To analyse the information from scientific literature about the effects of CR on clinical and cognitive variables of patients affected by disorders other than dementia. Development: A systematic search was conducted in the PubMed/Medline and ScienceDirect databases. A review was performed on articles that assessed the influence of CR in clinical and cognitive variables associated with disorders other than dementia. Empirical, longitudinal/transactional, and observational/quasi-experimental design studies were considered. The study finally included 107 research papers that fulfilled the established criteria. Results: Higher CR levels were associated with lower cognitive impairment in a wide variety of disorders, as well as with a better recovery on neurological, psychiatric or infectious conditions. Moreover, there is evidence on the CR role as a protective factor that could delay the development of neurological, neuropsychiatric, or infectious disorders. Limitations: As only 2 databases were searched, there may be more literature references on CR. Conclusion: CR proxies constitute a set of variables (cognitive, demographic, physical, etc.) that may have a significant influence on cognitive, clinical and functional aspects of different disorders. The need to conduct more research about the role of CR in the recovery process and as a protective factor in different disorders is highlighted

A Postmortem Study of Frontal and Temporal Gyri Thickness and Cell Number in Human Obesity.

OBJECTIVE: This study aimed to compare cortex thickness and neuronal cell density in postmortem brain tissue from people with overweight or obesity and normal weight. METHODS: The cortex thickness and neuron density of eight donors with overweight or obesity (mean = 31.6 kg/m2 ; SD = 4.35; n = 8; 6 male) and eight donors with normal weight (mean = 21.8 kg/m2 ; SD = 1.5; n = 8; 5 male) were compared. All participants were Mexican and lived in Mexico City. Randomly selected thickness measures of different cortex areas from the frontal and temporal lobes were analyzed based on high-resolution real-size photographs. A histological analysis of systematic-random fields was used to quantify the number of neurons in postmortem left and right of the first, second, and third gyri of frontal and temporal lobe brain samples. RESULTS: No statistical difference was found in cortical thickness between donors with overweight or obesity and individuals with normal weight. A smaller number of neurons was found among the donors with overweight or obesity than the donors with normal weight at different frontal and temporal areas. CONCLUSIONS: A lower density of neurons is associated with overweight or obesity. The morphological basis for structural brain changes in obesity requires further investigation.

Regulación Emocional En Pacientes Con Esquizofrenia: Un Estudio Piloto / Emotion Regulation In Schizophrenia Patients: A Pilot Study

RESUMEN Antecedentes: Se ha reportado que los pacientes con esquizofrenia presentan alteraciones en el procesamiento emocional, específicamente en la percepción de emociones. Sin embargo, poco se sabe sobre otros aspectos de este proceso, como la regulación emocional. Objetivo: Evaluar y comparar la regulación emocional y neurocognición en pacientes con esquizofrenia y sujetos control, así como identificar correlaciones entre regulación emocional, neurocognición y datos demográficos. Método: Se evaluaron nueve pacientes (GE) y nueve controles (GC). Se obtuvieron datos demográficos, para evaluar regulación emocional se utilizó la Prueba de Inteligencia Emocional Mayer-Salovey Caruso, sección Manejo de Emociones y se realizó una breve evaluación neurocognitiva. Resultados: El GE tuvo un desempeño significativamente inferior que el GC en la prueba de regulación emocional y en neurocognición (p<.05). No se encontraron correlaciones entre regulación emocional, neurocognición, datos demográficos y clínicos. Discusión y conclusión: Los pacientes con esquizofrenia presentan menor capacidad de regulación emocional y alteraciones en la neurocognición. Estos resultados son consistentes con lo descrito en la literatura.

ABSTRACT Background: It has been reported that schizophrenia patients display emotional processing impairments, specifically in the emotion perception domain. However, less is known about other domains of emotional processing, like emotion regulation. Objective: The aim of this study was to assess and compare emotion regulation abilities and neurocognition in schizophrenia patients and healthy controls, as well as to identify correlations between emotion regulation, neurocognition and demographic data. Methods: 9 patients (GE) and 9 controls (GC) were recruited. Demographic data was obtained. To assess emotion regulation, the Mayer-Salovey-Caruso Emotional Intelligence Test -Managing Emotions section- was administered. Finally, a brief neurocognitive assessment was conducted. Results: The GE showed significant poorer performance than the GC in the emotion regulation test as well as in the neurocognitive assessment (p < .05). No correlations were identified between emotion regulation, neurocognition, demographic and clinical data. Discussion and conclusion: Schizophrenia patients show emotion regulation impairment, as well as neurocognitive deficits. Our results are consistent with other studies.

Social Cognition in Schizophrenia, Unaffected Relatives and Ultra- High Risk for Psychosis: What Do We Currently Know?

INTRODUCTION: Schizophrenia patients show impairments in social cognition (SC), which is a set of cognitive processes that underlie social interactions. The research about SC in schizophrenia has identified four main domains: Theory of mind (ToM), social perception, attributional style and emotional processing. The present review aims to summarize the most recent and consistent findings about SC in patients with schizophrenia, unaffected relatives and ultra-high risk for psychosis individuals (UHR), as well as its association with clinical variables and functional outcome. METHODS: A systematic PsycINFO and Pubmed/Medline databases search was conducted. RESULTS: ToM impairments have been observed in schizophrenia patients, unaffected relatives and UHR. Emotional processing disturbance has been consistently reported in schizophrenia patients and UHR. ToM and emotional processing have been correlated with symptomatology and functional outcome. However, inconsistencies have been found across studies that assess ToM and emotional processing as predictors of psychosis. Social perception and attributional style are affected in schizophrenia, but the research in at- risk populations is scarce, and their relationship with symptoms or functional outcome is not clear. CONCLUSIONS: All domains of SC are impaired in schizophrenia. Non affected relatives and UHR also display deficits of SC. More research must be conducted to assess the reliability of SC domains as endophenotypes or predictors of conversion to psychosis in at-risk populations.

Cognición Social en Esquizofrenia, Familiares No Afectados e Individuos en Riesgo Ultra-Alto de Psicosis: ¿Qué Sabemos Actualmente? / Social Cognition in Schizophrenia, Unaffected Relatives and Ultra-High Risk for Psychosis: What Do We Currently Know?

Introducción. Los pacientes con esquizofrenia presentan alteraciones en cognición social (CS), que es un conjunto de procesos cognitivos que subyace a las interacciones sociales. En la investigación sobre CS en esquizofrenia se identifican cuatro componentes principales: teoría de la mente (TM), percepción social, estilo atributivo y procesamiento emocional. Este trabajo tiene como objetivo resumir los hallazgos más recientes y consistentes sobre la CS en pacientes con esquizofrenia, familiares no afectados e individuos en riesgo ultra-alto de psicosis (RUA), así como su asociación con variables clínicas y funcionalidad del paciente. Método.Se realizó una búsqueda sistematizada en las bases de datos PsycINFO y Pubmed/Medline. Resultados. Los déficits en TM se han observado en pacientes con esquizofrenia, familiares no afectados y sujeto en RUA. Se han reportado consistentemente alteraciones de procesamiento emocional en pacientes con esquizofrenia y RUA. La TM y el procesamiento emocional se correlacionan con sintomatología y funcionalidad. Sin embargo, existen inconsistencias en estudios sobre TM y procesamiento emocional como predictores de psicosis. La percepción social y el estilo atributivo están afectados en la esquizofrenia, pero la investigación en poblaciones en riesgo es escasa y su relación con la sintomatología y funcionalidad no es del todo clara. Conclusiones.Todos los componentes de la CS están alterados en la esquizofrenia. Los familiares no afectados y las personas en RUA también presentan déficits de CS. Se debe realizar más investigación sobre la confiabilidad de los componentes de la CS como endofenotipos o predictores de conversión a psicosis en poblaciones en riesgo (AU)

Introduction. Schizophrenia patients show impairments in social cognition (SC), which is a set of cognitive processes that underlie social interactions. The research about SC in schizophrenia has identified four main domains: Theory of mind (ToM), social perception, attributional style and emotional processing. The present review aims to summarize the most recent and consistent findings about SC in patients with schizophrenia, unaffected relatives and ultra-high risk for psychosis individuals (UHR), as well as its association with clinical variables and functional outcome. Methods. A systematic PsycINFO and Pubmed/Medline databases search was conducted. Results. ToM impairments have been observed in schizophrenia patients, unaffected relatives and UHR. Emotional processing disturbance has been consistently reported in schizophrenia patients and UHR. ToM and emotional processing have been correlated with symptomatology and functional outcome. However, inconsistencies have been found across studies that assess ToM and emotional process-ing as predictors of psychosis. Social perception and attributional style are affected in schizophrenia, but the research in at- risk populations is scarce, and their relationship with symptoms or functional outcome is not clear. Conclusions: All domains of SC are impaired in schizophrenia. Non affected relatives and UHR also display deficits of SC. More research must be conducted to assess the reliability of SC domains as endophenotypes or predictors of conversion to psychosis in at-risk populations (AU)

Mismatch Negativity reduction in the left cortical regions in first-episode psychosis and in individuals at ultra high-risk for psychosis.

Mismatch Negativity (MMN), an electrophysiological component that represents sensory memory processing, has been proposed as a potential vulnerability marker for psychosis. Some studies have reported a more evident MMN amplitude reduction in the left cortical regions in patients with schizophrenia. Little is known about this asymmetric pattern in patients in their first episode of psychosis (FEP) and individuals at ultra-high risk for psychosis (UHR). The aim of this study was to explore the scalp distribution of MMN in 20 FEP patients, 20 UHR subjects and 23 healthy controls. Both clinical groups were antipsychotic naïve. MMN was obtained during a passive auditory paradigm with duration deviant tones and analyzed from 15 frontocentral electrodes. There was a significant group effect in MMN amplitude (F=3.4, p=0.04), showing a decrement in both FEP and UHR compared to controls (FEP mean difference (MD)=-0.48, p=0.02; UHR MD=-0.44, p=0.04), and this amplitude decrement was more evident in the left middle regions for both clinical groups (p<0.01). In conclusion, we found a clear amplitude reduction of duration MMN in FEP patients and UHR individuals, especially in the left cortical regions. The observed pattern in both clinical samples supports the notion that MMN could be a vulnerability marker for psychosis. We propose to continue the study of this MMN laterality effect in future longitudinal studies.

Reduced P3a amplitudes in antipsychotic naïve first-episode psychosis patients and individuals at clinical high-risk for psychosis.

Event related potentials (ERP) associated with early sensory information processing have been proposed as possible vulnerability markers for psychosis. Compared to other ERPs reported in schizophrenia research, like Mismatch Negativity (MMN), little is known about P3a, an ERP related to novelty detection. The aim of this study was to analyze the MMN-P3a complex in 20 antipsychotic naïve first-episode psychosis patients (FEP), 23 antipsychotic naïve individuals at clinical high-risk for psychosis (CHR) and 24 healthy controls. The MMN-P3a amplitudes and latencies were obtained during a passive auditory mismatch frequency deviant ERP paradigm and analyzed in frontal and central scalp regions. There were no significant differences in MMN amplitude between groups. There was a significant group difference in P3a due to reduced amplitude (F[2,64] = 3.7, p = 0.03) in both CHR and FEP groups (Mean difference (MD) = 0.39, p = 0.04 and MD = 0.49, p = 0.02, respectively) compared to the control group and this effect was most prominent on the right side (Group × laterality effect: MD = 0.57, p < 0.01 and MD = 0.58, p < 0.01, respectively). No significant differences were observed for MMN or P3a latencies between groups. Although a P3a decrement in chronic schizophrenia and FEP has been previously reported, our results suggest that this novelty detection impairment is present even in pre-psychosis stages in antipsychotic naïve subjects. This study supports the evidence that P3a could represent a neurophysiological vulnerability marker for the development of psychosis.

[Mismatch Negativity (MMN) and schizophrenia: a revision]. / Mismatch Negativity (MMN) y esquizofrenia: una revisión.

The Mismatch Negativity (MMN) is an auditory Event- Related Potential which is generated as an automatic cerebral response to any change in the auditory stimulation that exceeds a limit corresponding to the discrimination threshold. It has been widely and consistently reported that patients with recent and chronic schizophrenia display smaller MMN amplitudes, suggesting that this component may be related with alteration in sensory memory and stimuli integration capacities, which seem to increase with the disease progression. Recently, new research areas have emerged, and studies of MMN of relatives of patients with schizophrenia have been conducted in order to assess the MMN efficacy as an endophenotype. Likewise, there have been MMN studies in schizophrenia prodromes or clinical high risk subjects, aiming to know if there are cerebral processing disturbances prior to the onset of the disease. The results of these studies have been promising, suggesting the presence of auditory stimuli processing disturbances in this population. These disturbances are subtle and seem to increase as the disease appears. The MMN component may be a very effective electrophysiological tool that provides information about the automatic auditory processing in schizophrenia related to its chronicity. It may also be a relative reliable index of genetic vulnerability and clinical risk for developing schizophrenia. Nevertheless, it is necessary to continue performing studies to get comparable and replicable studies in the future that could confirm the information about MMN utility.