RECURRENT SELF-LIMITED HYPERTHERMIA FOLLOWING ELECTROCONVULSIVE THERAPY.

Electroconvulsive therapy (ECT) is an effective and safe treatment for severe mental disorders, when it is implemented under an adequate surveillance. Its most frequently described side effects are anterograde amnesia, mania, post- ictal confusion, nausea, headache, myalgia, oral lacerations and dental injuries.

Progression of the functional deficit in a group of patients with bipolar disorder: a cluster analysis based on longitudinal data.

We aimed to examine the trajectory of psychosocial functioning in a sample of euthymic patients with bipolar disorder (BD) throughout a 5-year follow-up. Ninety-nine euthymic bipolar patients and 40 healthy controls (HC) were included. A neurocognitive assessment (17 neurocognitive measures grouped in 6 domains) was carried out at baseline. The split version of the Global Assessment of Functioning scale (GAF-F) and the Functioning Assessment Short Test (FAST) were used to examine psychosocial functioning at baseline (T1), and after a 5-year follow-up (T2). The statistical analysis was performed through repeated measures ANOVA and hierarchical cluster analysis based on the GAF-F and the FAST scores at T1 and T2. Eighty-seven patients (87.9%) were evaluated at T2. The cluster analysis identified two groups of patients. The first group included 44 patients (50.6%) who did not show a progression of the functional impairment (BD-NPI). The second cluster, which included 43 patients (49.4%), was characterized by a progression of the functional impairment (BD-PI). The BD-PI had a higher number of relapses and a higher number of hospitalizations during the follow-up period, as well as worse neurocognitive functioning than the BD-NPI. The repeated measures ANOVA confirmed that the psychosocial performance of BD-NPI is stable while there was a progression of the functional deterioration in BD-PI. The trajectory of the psychosocial functioning of patients with BD is not homogeneous. Our results suggest that in at least one subset of patients with BD, which might account for half of the patients, the disease has a progressive course.

Impact of number of episodes on neurocognitive trajectory in bipolar disorder patients: a 5-year follow-up study.

BACKGROUND: The neurocognitive trajectory in bipolar disorder (BD) is variable, with controversial findings, and most evidence come from cross-sectional studies. We aimed to examine the course of neurocognitive functioning in a sample of euthymic BD patients in comparison with a control group during a 5-year follow-up. METHODS: Ninety-nine euthymic bipolar patients and 40 healthy controls were assessed using a comprehensive neurocognitive battery (six neurocognitive domains) at baseline (T1) and then at 5-year follow-up (T2) in a longitudinal study. RESULTS: No evidence of a progression in neurocognitive dysfunction was found either in cognitive composite index or in any of the neurocognitive domains for the whole cohort. However, there was a negative correlation between number of manic episodes and hospitalisations due to manic episodes and change in neurocognitive composite index (NCI) during the follow-up. Moreover, patients with higher number of manic and hypomanic episodes have a greater decrease in NCI, working memory and visual memory. History of psychotic symptoms was not related to the trajectory of neurocognitive impairment. CONCLUSIONS: Our results suggest that, although the progression of cognitive decline is not a general rule in BD, BD patients who have a greater number of manic or hypomanic episodes may constitute a subgroup characterised by the progression of neurocognitive impairment. Prevention of manic and hypomanic episodes could have a positive impact on the trajectory of cognitive function.

A five-year follow-up study of neurocognitive functioning in bipolar disorder.

OBJECTIVES: Cognitive dysfunction in bipolar disorder has been well-established in cross-sectional studies; however, there are few data regarding the longitudinal course of cognitive performance in bipolar disorder. The aim of this study was to examine the course of cognitive function in a sample of euthymic patients with bipolar disorder during a five-year follow-up period. METHODS: Eighty euthymic outpatients with a DSM-IV diagnosis of bipolar disorder and 40 healthy control comparison subjects were neuropsychologically assessed at baseline (T1) and then at follow-up of five years (T2). A neurocognitive battery including the main cognitive domains of speed of processing, working memory, attention, verbal memory, visual memory, and executive function was used to evaluate cognitive performance. RESULTS: Repeated-measures multivariate analyses showed that progression of cognitive dysfunction in patients was not different to that of control subjects in any of the six cognitive domains examined. Only a measure from the verbal memory domain, delayed free recall, worsened more in patients with bipolar disorder. Additionally, it was found that clinical course during the follow-up period did not influence the course of cognitive dysfunction. CONCLUSIONS: Cognitive dysfunction that is characteristic of bipolar disorder is persistent and stable over time. Only dysfunction in verbal recall was found to show a progressive course that cannot be explained by clinical or treatment variables.

Negative symptoms and executive function in schizophrenia: does their relationship change with illness duration?

BACKGROUND: Negative symptoms and cognitive dysfunction are of crucial functional and prognostic importance in schizophrenia. However, the nature of the relationship between them and the factors that may influence it have not been well established. AIMS: To investigate whether the relationship between negative symptoms and executive function changes according to the duration of illness in schizophrenia. METHODS: The Positive and Negative Syndrome Scale was used to assess psychopathology and the Wisconsin Card Sorting Test (WCST) to evaluate executive function in a sample of 200 schizophrenic patients who were classified in 3 groups according to their duration of illness: up to 5 years (short duration group), 6-20 years (intermediate duration group) and over 20 years of illness (long duration group). RESULTS: Medium-sized correlations were found between negative symptoms and WCST performance as assessed by the number of completed categories in all 3 groups. However, differences were found according to the duration of schizophrenia. For patients in the short duration group, negative symptoms correlated with WCST nonperseverative errors, but for those in the long duration group the correlation was with perseverative errors. CONCLUSION: We found a differential relationship between negative and cognitive symptoms in different stages of schizophrenia. Illness duration should be considered when studying the relationship between negative symptoms and cognition.

Objective Diagnosis of Fibromyalgia Using Neuroretinal Evaluation and Artificial Intelligence.

Background/Objective: This study aims to identify objective biomarkers of fibromyalgia (FM) by applying artificial intelligence algorithms to structural data on the neuroretina obtained using swept-source optical coherence tomography (SS-OCT). Method: The study cohort comprised 29 FM patients and 32 control subjects. The thicknesses of complete retina, 3 retinal layers [ganglion cell layer (GCL+), GCL++ (between the inner limiting membrane and the inner nuclear layer boundaries) and retinal nerve fiber layer (RNFL)] and choroid in 9 areas around the macula were obtained using SS-OCT. Discriminant capacity was evaluated using the area under the curve (AUC) and the Relief algorithm. A diagnostic aid system with an automatic classifier was implemented. Results: No significant difference (p ≥ .660) was found anywhere in the choroid. In the RNFL, a significant difference was found in the inner inferior region (p = .010). In the GCL+, GCL++ layers and complete retina, a significant difference was found in the 4 regions defining the inner ring: temporal, superior, nasal and inferior. Applying an ensemble RUSBoosted tree classifier to the features with greatest discriminant capacity achieved accuracy = .82 and AUC = .82. Conclusions: This study identifies a potential novel objective and non-invasive biomarker of FM based on retina analysis using SS-OCT.

Antecedentes/Objetivo: Identificar biomarcadores objetivos de fibromialgia (FM) aplicando inteligencia artificial a datos estructurales de retina obtenidos mediante tomografía de coherencia óptica Swept Source (TCO-SS). Método: Se evaluó una cohorte de 29 pacientes con FM y otra de 32 sujetos control, registrando los espesores de la retina completa, de varias capas de la retina [capa de células ganglionares (CCG+), CCG ampliada (CCG++, entre la membrana limitante interna y los límites de la capa nuclear interna) y capa de fibras nerviosas (CFNR)] y de la coroides, mediante TCO-SS. La capacidad discriminante se evaluó mediante el área bajo la curva ROC (AROC) y el algoritmo Relief. Se implementó un sistema de ayuda al diagnóstico con clasificador automático. Resultados: No se observó diferencia significativa (p ≥ .660) en la coroides, pero sí en el sector inferior del anillo interno de la CFNR (p = .010) y en los cuatro sectores del anillo interno en las capas CCG+, CCG++ y retina completa. Utilizando un árbol de decisión ensemble RUSBoosted como clasificador de las características con mayor capacidad discriminante, se obtuvo una predicción alta (AROC=.820). Conclusiones: Se identifica un potencial biomarcador objetivo y no invasivo para el diagnóstico de FM basado en el análisis de la neurorretina mediante TCO-SS.

Neurocognition, functional outcome, and quality of life in remitted and non-remitted schizophrenia: A comparison with euthymic bipolar I disorder and a control group.

There are discrepancies about if the severity of the symptomatology in schizophrenia is related to neurocognitive performance, functional outcome, and quality of life (QoL). Also, there are controversial data about the comparison between euthymic bipolar patients and different subgroups of schizophrenia in neurocognition, functioning, and QoL level. The present study aimed to compare the neurocognitive performance, functional outcome, and QoL of remitted and non-remitted patients with SC with respect to a group of euthymic patients with BD, and a control group. It included 655 subjects: 98 patients with schizophrenia in remission (SC-R), 184 non-remitted patients with schizophrenia (SC-NR), 117 euthymic patients with bipolar I disorder (BD), and 256 healthy subjects. A comprehensive clinical, neurocognitive (six cognitive domains), functional, and QoL assessment was carried out. Remission criteria of Andreasen were used to classify schizophrenia patients as remitted or non-remitted. Compared with control subjects all groups of patients showed impaired neurocognitive performance, functioning and QoL. SC-R patients had an intermediate functioning between control subjects and SC-NR, all at a neurocognitive, functional, or QoL level. There were no significant differences between SC-R and BD. These results suggest that reaching clinical remission is essential to achieve a better level of psychosocial functioning, and QoL. Likewise, the results of this study suggest that euthymic patients with bipolar disorder and patients with schizophrenia in remission are comparable at the neurocognitive and functional levels, which might have implications in the pathophysiology of both disorders.

Predictive factors of functional outcome in patients with bipolar I disorder: a five-year follow-up.

BACKGROUND: Functional impairment is commonly encountered among patients with bipolar disorder (BD) during periods of remission. The distribution of the impairment of the functional outcome is heterogeneous. The objective of this current investigation was to identify neurocognitive and clinical predictors of psychosocial functioning in a sample of patients with BD. METHODS: Seventy-six patients (59.2% females) and 40 healthy controls (50% females), aged 18 to 55 years, were assessed using a comprehensive neurocognitive battery (six neurocognitive domains), and the Functioning Assessment Short Test (FAST), at baseline and after a 5-year follow-up. Stepwise regression models were used to identify predictor variables related to psychosocial functioning. RESULTS: The number of hospitalizations during the follow-up, the change occurred in the neurocognitive composite index (NCI change), and NCI at baseline explained 30.8% of the variance of functioning. The number of hospitalizations during the follow-up was the variable that explained a greater percentage of the variance (16.9%). Verbal memory at baseline and the change in sustained attention during the follow-up explained 10% and 5.9% of the variance of the psychosocial functioning, respectively. LIMITATIONS: The interval of 5 years between the two assessments could be too short to detect a possible progression in functional outcome for the overall sample. CONCLUSIONS: The clinical course during the follow-up is the factor that has a greater impact on psychosocial functioning in patients with BD. Thus, the interventions aimed to promote prevention of relapses should be considered as essential for avoiding functional impairment in these patients.

Comparative study of neurocognitive function in euthymic bipolar patients and stabilized schizophrenic patients.

Few studies have compared neurocognitive performance in euthymic patients with bipolar disorder (BD), stabilized patients with schizophrenia (SC) and normal controls (NC) using a comprehensive neuropsychological battery, and those that have been conducted have yielded discrepant results. We evaluated the neurocognitive profile shown by 73 euthymic patients with BD, 89 stabilized patients with SC and 67 NC. All participants completed a cognitive battery in which the domains evaluated were executive functioning, sustained attention, and verbal and visual memory. Individuals with BD were administered the Quality of Life Scale (QLS). Patients with BD manifested dysfunction in executive functioning (moderate-to-large effect size), sustained attention (moderate effect size) and verbal/visual memory (large effect size) compared with NC. Verbal memory deficit in patients with BD was related to poor functional outcome on the QLS and Global Assessment of Functioning (GAF). Patients with BD performed significantly better than patients with SC on the Trail Making Test (TMT) part B, backward digit span, and California Verbal Learning Test (CVLT) learning trials. Other neuropsychological measures showed no significant differences between the two patient groups. These findings support the notion that euthymic BD patients suffer from an extensive neurocognitive deficit that affects all cognitive domains and is qualitatively similar to that in SC patients. Persistent verbal memory impairment in BD has clinical relevance because it is associated with poor psychosocial function.

Neurocognition and functional outcome in patients with psychotic, non-psychotic bipolar I disorder, and schizophrenia. A five-year follow-up.

BACKGROUND: Bipolar disorder (BD) and schizophrenia (SZ) are characterized by neurocognitive and functional deficits with marked heterogeneity. It has been suggested that BD with a history of psychotic symptoms (BD-P) could constitute a phenotypically homogeneous subtype characterized by greater neurocognitive and functional impairments, or by a distinct trajectory of such deficits. The aim of this study was to compare the neurocognitive and functional course of euthymic BD-P, euthymic BD patients without a history of psychosis (BD-NP), stabilized patients with schizophrenia and healthy subjects, during a five-year follow-up. METHODS: Neurocognitive and psychosocial function was examined in 100 euthymic patients with BD (50 BD-P, 50 BD-NP), 50 stabilized patients with schizophrenia (SZ), and 51 healthy controls (HC) at baseline (T1), and after a 5-year follow-up (T2). RESULTS: The course of both neurocognitive performance and functional outcome of patients with SZ and BD (BD-P and BD-NP) is stable. The profile of neurocognitive impairment of patients with SZ or BD (BD-P and BD-NP), is similar, with only quantitative differences circumscribed to certain domains, such as working memory. The subgroup of patients with BD-NP does not show functional deterioration. CONCLUSIONS: We have not found evidence of progression in the neurocognitive or psychosocial impairment in any of the three groups of patients, although it cannot be dismissed the possibility of a subset of patients with a progressive course. Other longitudinal studies with larger samples and longer duration are necessary to confirm these findings.

Long-acting injectable antipsychotics for the treatment of schizophrenia in Spain. / Antipsicóticos inyectables de liberación prolongada para el tratamiento de la esquizofrenia en España.

Antipsychotics are an essential component in the treatment of schizophrenia. Long-acting injectable formulations (LAI) arose to improve adherence with the associated potential of reducing the risk of relapse. The objective of this article is to analyze the use of LAI antipsychotics in Spain, which is similar to other European countries but with a predominance of the use of second generation LAI, to discuss the possible causes of prescribing differences with respect to other countries (including organizational aspects, attitudes of psychiatrists, patients and family members, and clinical practice guidelines), and to discuss their use in acute psychiatric units, first episode, and in children and adolescents. In our view, while it is necessary to increase existing evidence regarding the advantages of LAI antipsychotics and the differentiation between LAI antipsychotics currently available, their use will likely continue to grow driven by clinical experience.

Psychosocial functioning in patients with psychotic and non-psychotic bipolar I disorder. A comparative study with individuals with schizophrenia.

BACKGROUND: More than 50% of individuals with bipolar disorder (BD) do not reach full psychosocial functioning, even during periods of euthymia. It has been suggested that history of psychotic symptoms is one of the factors which are associated with a worse functional outcome. The objective was to compare psychosocial functioning between patients with BD, with (BD-P), and without (BD-NP) a history of psychotic symptoms, and to examine whether the history of psychotic symptoms, or other clinical or neurocognitive variables predict psychosocial functioning. METHODS: Psychosocial functioning and neurocognition were examined in 100 euthymic patients with bipolar I disorder (50 BD-P, and 50 BD-NP), compared to 50 stabilised patients with schizophrenia (SZ), and 51 healthy controls (HC). RESULTS: 1) There were no differences between BD-P and BD-NP in the GAF-F score or in the FAST total score. 2) The two groups of patients with BD had better scores than SZ both in the GAF-F, and in all measures of the FAST, except for the subscale leisure time. 3) The neurocognitive composite index, verbal memory and subclinical depressive symptoms were the variables which explained a higher percentage of the variance of functional outcome. LIMITATIONS: The cross-sectional design, and the relatively small sample size are the main limitations. CONCLUSIONS: A history of psychotic symptoms has no relevant impact on the level of psychosocial functioning in BD. Neurocognitive dysfunction and subclinical depressive symptoms are the variables that best explain the functional impairment. These findings have important clinical implications.

Neurocognition in patients with psychotic and non-psychotic bipolar I disorder. A comparative study with individuals with schizophrenia.

BACKGROUND: It has been suggested that patients with bipolar disorder with psychotic symptoms (BD-P) have larger neurocognitive impairment than patients with bipolar disorder without a history of psychotic symptoms (BD-NP). The objective of this study was to compare neurocognitive performance of BD-P and BD-NP relative to a group of patients with schizophrenia (SZ), and healthy controls (HC). METHODS: Neurocognitive function was examined in 100 subjects with bipolar I disorder (50 BD-P, 50 BD-NP), 50 SZ, and 51 HC. All patients with BD fulfilled criteria for euthymia, while all SZ patients were stabilised for at least the previous 3 months. RESULTS: Patients with BD-P and BD-NP performed worse than HC in all neurocognitive measures, except for sustained attention. Differences between BD-P and BD-NP were subtle and circumscribed to the working memory domain (effect size: 0.29). SZ performed worse than BD-NP in the neurocognitive composite index (NCI) and in the working memory domain. There were no differences between SZ and BD-P in any neurocognitive measure. LIMITATIONS: The relatively small sample size, the cross-sectional design and, that patients were receiving pharmacological treatment are the main limitations of this study. CONCLUSIONS: Our findings show that the three groups of patients have a large neurocognitive impairment. Differences are quantitative and only present in some neurocognitive domains, such as working memory. These results suggest that patients with BD and SZ can benefit from the same strategies of cognitive remediation.

Objective Diagnosis of Fibromyalgia Using Neuroretinal Evaluation and Artificial Intelligence / Diagnóstico objetivo de fibromialgia analizando la neurorretina con inteligencia artificial

ResumenAntecedentes/Objetivo: Identificar biomarcadores objetivos de fibromialgia (FM) apli-cando inteligencia artificial a datos estructurales de retina obtenidos mediante tomogra-fía de coherencia óptica Swept Source (TCO-SS). Método: Se evaluó una cohorte de 29 pacientes con FM y otra de 32 sujetos control, registrando los espesores de la retina completa, de varias capas de la retina [capa de células ganglionares (CCG+), CCG amplia-da (CCG++, entre la membrana limitante interna y los límites de la capa nuclear interna) y capa de fibras nerviosas (CFNR)] y de la coroides, mediante TCO-SS. La capacidad dis-criminante se evaluó mediante el área bajo la curva ROC (AROC) y el algoritmo Relief. Se implementó un sistema de ayuda al diagnóstico con clasificador automático. Resultados: No se observó diferencia significativa (p ≥ 0,660) en la coroides, pero sí en el sector in-ferior del anillo interno de la CFNR (p = 0,010) y en los cuatro sectores del anillo interno en las capas CCG+, CCG++ y retina completa. Utilizando un árbol de decisión ensemble RUSBoosted como clasificador de las características con mayor capacidad discriminante, se obtuvo una predicción alta (AROC = 0,820). Conclusiones: Se identifica un potencial biomarcador objetivo y no invasivo para el diagnóstico de FM basado en el análisis de la neurorretina mediante TCO-SS.

AbstractBackground/Objective: This study aims to identify objective biomarkers of fibromyalgia (FM) by applying artificial intelligence algorithms to structural data on the neuroretina obtained using swept-source optical coherence tomography (SS-OCT). Method: The study cohort comprised 29 FM patients and 32 control subjects. The thicknesses of complete retina, 3 retinal layers [ganglion cell layer (GCL+), GCL++ (between the inner limiting membrane and the inner nuclear layer boundaries) and retinal nerve fiber layer (RNFL)] and choroid in 9 areas around the macula were obtained using SS-OCT. Discriminant capacity was evaluated using the area under the curve (AUC) and the Relief algorithm. A diagnostic aid system with an automatic classifier was implemented. Results: No significant difference (p ≥ .660) was found anywhere in the choroid. In the RNFL, a significant difference was found in the inner inferior region (p = .010). In the GCL+, GCL++ layers and complete retina, a significant difference was found in the 4 regions defining the inner ring: temporal, superior, nasal and inferior. Applying an ensemble RUSBoosted tree classifier to the features with greatest discriminant capacity achieved accuracy = .82 and AUC = .82. Conclusions: This study identifies a potential novel objective and non-invasive biomarker of FM based on retina analysis using SS-OCT.

Long range frontal/posterior phase synchronization during remembered pursuit task is impaired in schizophrenia.

Although smooth pursuit eye movement (SPEM) is a reliable endophenotype of schizophrenia, exact underlying cognitive and neural substrates remain unknown. A simple mechanistic model of SPEM assumes an efficient interaction in integrating sensory input from the medial temporal (MT)/medial superior temporal (MST) brain regions and subsequent motor response through the frontal eye field (FEF). Poor functional connectivity between these two regions could explain impaired motion perception and SPEM maintenance in schizophrenia. In the present study, we combined an eye tracking paradigm with electroencephalography (EEG) recordings to investigate the putative functional connectivity among frontal/posterior brain regions in mediating the modulation of SPEM. Twenty four schizophrenic (SZ) and 22 healthy control (HC) participants performed remembered pursuit tasks with EEG recordings. Behaviorally, HC subjects showed significant improvement in SPEM response on repeated presentations of target compared to SZ subjects. Neurophysiologically HC subjects showed higher frontal/posterior phase synchronization in the beta to low gamma range frequency bands during all target presentations. In addition there was a significant increase in phase synchronization in the beta-2 frequency band in HC subjects during late compared to early target presentation. In contrast, higher frontal/posterior phase synchronization in the beta-2 frequency predicted better performance during late target presentation and lower enduring psychosis in SZ subjects. These data suggest a pathologically perturbed connectivity between frontal and posterior cortical regions during SPEM in SZ. The integrative eye tracking-EEG approach used in this study to dissect the endophenotype may reveal novel targets for studying schizophrenia psychopathology.

Antipsicóticos inyectables de liberación prolongada para el tratamiento de la esquizofrenia en España / Long-acting injectable antipsychotics for the treatment of schizophrenia in Spain

Los antipsicóticos son un componente esencial del tratamiento de la esquizofrenia. Las formulaciones inyectables de liberación prolongada (ILP) surgen para mejorar la adherencia con el potencial asociado de reducir el riesgo de recaídas. El objetivo de este artículo es analizar el uso de antipsicóticos ILP en España -que es similar al de otros países europeos pero con un predominio de la utilización de ILP de segunda generación-, discutir las posibles causas de las diferencias de prescripción respecto a otros países de nuestro entorno (entre otras, aspectos organizativos, actitudes de psiquiatras, pacientes y familiares, guías de práctica clínica), y discutir su utilización en unidades de agudos, primeros episodios, y en niños y adolescentes. A nuestro juicio, aunque es necesario aumentar las pruebas existentes respecto a las ventajas de los antipsicóticos ILP y la diferenciación entre aquellos disponibles actualmente, su utilización seguirá probablemente creciendo impulsada por la experiencia clínica

Antipsychotics are an essential component in the treatment of schizophrenia. Long-acting injectable formulations (LAI) arose to improve adherence with the associated potential of reducing the risk of relapse. The objective of this article is to analyze the use of LAI antipsychotics in Spain, which is similar to other European countries but with a predominance of the use of second generation LAI, to discuss the possible causes of prescribing differences with respect to other countries (including organizational aspects, attitudes of psychiatrists, patients and family members, and clinical practice guidelines), and to discuss their use in acute psychiatric units, first episode, and in children and adolescents. In our view, while it is necessary to increase existing evidence regarding the advantages of LAI antipsychotics and the differentiation between LAI antipsychotics currently available, their use will likely continue to grow driven by clinical experience

Neuropsychological correlates of P50 sensory gating in patients with schizophrenia.

Impaired inhibition of P50 cerebral evoked response is one of the best validated endophenotypes in schizophrenia. There are controversial data on the relationship between P50 evoked potential deficit and measures of cognitive function in schizophrenia. A comprehensive clinical and neurocognitive assessment plus an evaluation of P50 sensory gating was performed in 160 schizophrenia patients and 64 controls. Neurocognitive scores from each cognitive domain were converted to demographically-adjusted T-scores (age, gender, and years of education) for all study participants. The relationship between P50 and neurocognitive variables was assessed via parametric and nonparametric correlations and categorical strategies: we compared neuropsychological test scores in patients and controls in the lowest P50 quartile vs. the highest. Controls had better performance than schizophrenia patients in all cognitive domains. Schizophrenia patients had significantly higher P50 ratios than controls, and no significant correlation was found between P50 gating measures and neuropsychological test scores in schizophrenia patients or healthy controls. Moreover, no differences in neurocognitive performance were found between subjects in the lowest P50 ratio quartile vs. the highest in healthy controls or patients with schizophrenia. We concluded that there is no evidence of an association between P50 ratio and cognitive measures in schizophrenia patients, and this seems to be also the case in healthy controls.

Cognition and the five-factor model of the positive and negative syndrome scale in schizophrenia.

Different exploratory and confirmatory factorial analyses of the Positive and Negative Syndrome Scale (PANSS) have found a number of factors other than the original positive, negative, and general psychopathology. Based on a review of previous studies and using confirmatory factor analyses (CFA), Wallwork et al. (Schizophr Res 2012; 137: 246-250) have recently proposed a consensus five-factor structure of the PANSS. This solution includes a cognitive factor which could be a useful measure of cognition in schizophrenia. Our objectives were 1) to study the psychometric properties (factorial structure and reliability) of this consensus five-factor model of the PANSS, and 2) to study the relationship between executive performance assessed using the Wisconsin Card Sorting Test (WCST) and the proposed PANSS consensus cognitive factor (composed by items P2-N5-G11). This cross-sectional study included a final sample of 201 Spanish outpatients diagnosed with schizophrenia. For our first objective, CFA was performed and Cronbach's alphas of the five factors were calculated; for the second objective, sequential linear regression analyses were used. The results of the CFA showed acceptable fit indices (NNFI=0.94, CFI=0.95, RMSEA=0.08). Cronbach's alphas of the five factors were adequate. Regression analyses showed that this five-factor model of the PANSS explained more of the WCST variance than the classical three-factor model. Moreover, higher cognitive factor scores were associated with worse WCST performance. These results supporting its factorial structure and reliability provide robustness to this consensus PANSS five-factor model, and indicate some usefulness of the cognitive factor in the clinical assessment of schizophrenic patients.

P50 gating in deficit and nondeficit schizophrenia.

Dysfunctional auditory sensory processing has generally been found in schizophrenia and it has been suggested that these deficits might be related to clinical and psychosocial variables. The present study included P50 recordings using a simple-paired click auditory evoked potential paradigm in sixty patients with deficit schizophrenia (DS), sixty patients with nondeficit schizophrenia (NDS), and sixty comparison subjects. The Schedule for the Deficit Syndrome was used to categorize patients as DS or NDS. The two patient groups did not differ in clinical variables, except for higher negative dimension and lower community outcome scores in DS than in NDS patients. There were no differences in P50 ratios between deficit and nondeficit subgroups; compared with normal subjects both groups of schizophrenia patients showed impaired P50 ratios (p<0.0001). This ratio appears to be independent of positive and negative symptoms. However, impairment in P50 gating correlated with poorer community outcome. The data document the existence of early auditory sensory processing abnormalities in DS and NDS, and might suggest that common neuronal network abnormalities underlie both forms of schizophrenia. Deficient P50 gating may be associated with impaired functional outcome in schizophrenia.

Executive function in schizophrenia: influence of substance use disorder history.

Cognitive function in schizophrenia has been associated with different sociodemographic and clinical variables. Substance use disorder (SUD) history has also been associated with cognition in schizophrenia; however, contradictory results have been found regarding its influence on cognitive function. Our aim was to study the relationship between executive function and a) age, b) duration of illness, c) number of psychotic episodes, d) positive symptoms, and e) negative symptoms, in a sample of schizophrenic patients, and secondly to study whether these relationships persisted after stratification of the sample according to the presence or absence of SUD history. A final sample of 203 schizophrenic patients were evaluated for psychotic symptoms using the PANSS, and assessed using a neuropsychological battery to calculate a composite executive function score. Linear regression analyses were performed, with this executive score as the dependent variable, and age, duration of illness, number of psychotic episodes, positive PANSS score and negative PANSS score as independent variables. For the total sample, the regression model showed three variables to be significant predictors of the executive score: age (p=0.004), number of episodes (p=0.027), and PANSS negative score (p=0.003). However, once the sample was stratified, the regression model showed age (p=0.011) and number of episodes (p=0.011) to be predictor variables for the executive score in the group of schizophrenic patients with SUD history, while age (p=0.028) and PANSS negative score (p=0.006) were predictors in the group of schizophrenic patients without such history. These findings highlight the importance of considering SUD history in studies of cognitive function in schizophrenia.