Modelo predictivo de la funcionalidad en la esquizofrenia: una aproximación desde el modelado de ecuaciones estructurales / An outcome prediction model for schizophrenia: a structural equation modelling approach

Introducción: Aunque la relación de los síntomas y las funciones cognitivas con la funcionalidad de pacientes con esquizofrenia es bien conocida, la complejidad de la patología hace necesario el estudio de esta relación por medio de un método más analítico que los enfoques de relaciones simples. Material y métodos: Ciento sesenta y cinco pacientes con esquizofrenia se sometieron a una evaluación clínica (síntomas clínicos, insight, síntomas afectivos y ajuste premórbido). La neurocognición fue representada mediante una estructura de 5 factores obtenida por medio del análisis factorial confirmatorio. La funcionalidad se obtuvo mediante la escala DAS-WHO y la calidad de vida mediante la Escala de Calidad de Vida. Resultados: Utilizando el modelado de ecuaciones estructurales (MEE), específicamente el «measured-variable path analysis», el modelo de mediación formado por la capacidad neurocognitiva, los síntomas clínicos y el funcionamiento premórbido mostró un buen ajuste con los datos observados (Satorra-Bentler χ2=604,83; RMSEA=0,08; SRMR=0,11; NNFI=0,96; CFI=0,97). La velocidad de procesamiento, la memoria verbal y el funcionamiento premórbido predijeron directamente la funcionalidad. La fluidez verbal predijo la funcionalidad de manera directa e indirecta, a través de los síntomas negativos. Las funciones ejecutivas, el insight, los síntomas afectivos y los datos cognitivos adicionales no contribuyeron de manera significativa al modelo. Conclusiones: Los resultados indican que los síntomas negativos y el funcionamiento premórbido predicen directamente la funcionalidad, mientras que los factores cognitivos muestran interacciones más complejas con los síntomas negativos y la funcionalidad. Estos resultados deberían ser considerados para nuevas estrategias de intervención

Introduction: Although it is well-known that several factors such as symptoms and cognition are related with functional outcome in schizophrenia, the complex nature of the disorder makes necessary to study their interaction by means of a more analytic method than simple linkages approaches. Material and methods: One hundred and sixty-five patients with schizophrenia underwent a clinical evaluation (including clinical symptoms, insight, affective symptoms and premorbid adjustment). Neurocognition was represented by a 5-factor structure obtained by confirmatory factor analysis from a neurocognitive battery. The estimation for outcome was obtained throughout the DAS-WHO scale, and quality of life with the Quality of Life Scale. Results: Using structural equation modeling (SEM), specifically measured-variable path analysis, a mediational model consisting of neurocognitive capacity linked to clinical symptoms and premorbid functioning showed good fit to the observed data (Satorra-Bentler χ2=604.83; RMSEA=.08; SRMR=.11; NNFI=.96; CFI=.97). Processing speed, verbal memory and premorbid functioning directly predicted outcome. Verbal fluency predicted outcome both directly and indirectly via negative symptoms. Executive functions, insight, affective symptoms, and additional cognitive data did not significantly contribute to the model. Conclusions: Results suggest that negative symptoms and premorbid functioning directly predict outcome, whereas cognitive factors show more complex interactions with negative symptoms and outcome. These results should be considered for new intervention strategies

An outcome prediction model for schizophrenia: A structural equation modelling approach. / Modelo predictivo de la funcionalidad en la esquizofrenia: una aproximación desde el modelado de ecuaciones estructurales.

INTRODUCTION: Although it is well-known that several factors such as symptoms and cognition are related with functional outcome in schizophrenia, the complex nature of the disorder makes necessary to study their interaction by means of a more analytic method than simple linkages approaches. MATERIAL AND METHODS: One hundred and sixty-five patients with schizophrenia underwent a clinical evaluation (including clinical symptoms, insight, affective symptoms and premorbid adjustment). Neurocognition was represented by a 5-factor structure obtained by confirmatory factor analysis from a neurocognitive battery. The estimation for outcome was obtained throughout the DAS-WHO scale, and quality of life with the Quality of Life Scale. RESULTS: Using structural equation modeling (SEM), specifically measured-variable path analysis, a mediational model consisting of neurocognitive capacity linked to clinical symptoms and premorbid functioning showed good fit to the observed data (Satorra-Bentler χ2=604.83; RMSEA=.08; SRMR=.11; NNFI=.96; CFI=.97). Processing speed, verbal memory and premorbid functioning directly predicted outcome. Verbal fluency predicted outcome both directly and indirectly via negative symptoms. Executive functions, insight, affective symptoms, and additional cognitive data did not significantly contribute to the model. CONCLUSIONS: Results suggest that negative symptoms and premorbid functioning directly predict outcome, whereas cognitive factors show more complex interactions with negative symptoms and outcome. These results should be considered for new intervention strategies.

Improvements in negative symptoms and functional outcome after a new generation cognitive remediation program: a randomized controlled trial.

Cognitive remediation improves cognition in patients with schizophrenia, but its effect on other relevant factors such as negative symptoms and functional outcome has not been extensively studied. In this hospital-based study, 84 inpatients with chronic schizophrenia were recruited from Alava Hospital (Spain). All of the subjects underwent a baseline and a 3-month assessment that examined neurocognition, clinical symptoms, insight, and functional outcome according to the Global Assessment of Functioning (GAF) scale and Disability Assessment Schedule from World Health Organization (DAS-WHO). In addition to receiving standard treatment, patients were randomly assigned either to receive neuropsychological rehabilitation (REHACOP) or to a control group. REHACOP is an integrative program that taps all basic cognitive functions. The program included experts' latest suggestions about positive feedback and activities of daily living in the patients' environment. The REHACOP group showed significantly greater improvements at 3 months in the areas of neurocognition, negative symptoms, disorganization, and emotional distress compared with the control group (Cohen's effect size for these changes ranged from d = 0.47 for emotional distress to d = 0.58 for disorganization symptoms). The REHACOP group also improved significantly in both the GAF (d = 0.61) and DAS-WHO total scores (d = 0.57). Specifically, the patients showed significant improvement in vocational outcomes (d = 0.47), family contact (d = 0.50), and social competence (d = 0.56). In conclusion, neuropsychological rehabilitation may be useful for the reduction of negative symptoms and functional disability in schizophrenia. These findings support the integration of neuropsychological rehabilitation into standard treatment programs for patients with schizophrenia.

Evidencias de eficacia de la rehabilitación cognitiva en psicosis y esquizofrenia con el programa REHACOP. Réplica / Evidence of the effectiveness of cognitive rehabilitation in psychosis and schizophrenia with the REHACOP programme. Reply

No disponible

The course of the schizophrenia and its impact on cognition: a review of literature.

There has been increasing interest about cognition in schizophrenia during recent years. The greater focus of the investigators has been focused greater interest on the relation of cognitive deterioration with positive and negative symptoms, and functionality. However very few studies, if any, have specifically focused on the course of cognition in schizophrenic patients throughout the years. Those who have attempted to answer this question have done so by comparing cross-sectional studies of patients at different stages of their disease. Only a minority have used a longitudinal methodology in their studies. This article reviews a total of 31 cross-sectional and 43 longitudinal studies published in patients with a diagnosis of schizophrenia. The diversity of criteria and methods used significantly limits the conclusions that can be drawn. After a comprehensive review of the literature on this topic, the authors have come to the conclusion that there are two opposite trends: 1) Cognition in schizophrenia follows a progressive decline over the years of evolution of the disease (a conclusion predominant in studies with cross-sectional methodology) and 2) Cognition in schizophrenia remains stable once it appears during the first stages of the disease (a conclusion predominant in longitudinal studies). The authors conclude that the question about the likely decline of cognition in schizophrenia cannot be answered due to the lack of rigorous and thorough follow-up studies.

Curso evolutivo de la esquizofrenia y su impacto en la cognición: una revisión de la literatura / The course of the schizophrenia and its impact on cognition: a review of literature

Durante los últimos años ha habido un creciente interés sobre el problema de la cognición en la esquizofrenia. El mayor foco de interés de los investigadores ha descansado sobre la relación del deterioro cognitivo con los síntomas positivos y negativos de la enfermedad así como con la funcionalidad. Sin embargo muy pocos estudios se han centrado, específicamente, en determinar el curso del deterioro cognitivo a lo largo de la evolución de la enfermedad. La mayoría de quienes lo han intentando han empleado una metodología consistente en comparar transversalmente el estatus cognitivo de pacientes en diversos estadios evolutivos de la enfermedad. Solo una minoría ha empleado una metodología longitudinal. Este artículo revisa un total de 31 estudios transversales y 43 longitudinales en pacientes con esquizofrenia. La gran variabilidad de criterios y métodos dificulta enormemente la obtención de conclusiones a partir de los diversos hallazgos. Tras una exhaustiva revisión de la literatura sobre este asunto, los autores aprecian que hay dos tendencias principales: 1) El deterioro cognitivo evoluciona progresivamente a lo largo de la enfermedad (tesis predominante en los estudios de metodología transversal)y 2) El deterioro cognitivo permanece estable una vez que hace aparición (la tesis predominante de los estudios longitudinales). Los autores concluyen que la pregunta sobre la posible evolución del deterioro cognitivo no puede aún ser respondida por la carencia de suficientes estudios longitudinales con metodología rigurosa y suficientemente extensos (AU)

There has been increasing interest about cognition in schizophrenia during recent years. The greater focus of the investigators has been focused greater interest on the relation of cognitive deterioration with positive and negative symptoms, and functionality. However very few studies, if any, have specifically focused on the course of cognition in schizophrenic patients throughout the years. Those who have attempted to answer this question have done so by comparing cross-sectional studies of patients at different stages of their disease. Only a minority have used a longitudinal methodology in their studies. This article reviews a total of 31 cross-sectional and 43 longitudinal studies published in patients with a diagnosis of schizophrenia. The diversity of criteria and methods used significantly limits the conclusions that can be drawn. After a comprehensive review of the literature on this topic, the authors have come to the conclusion that there are two opposite trends: 1) Cognition in schizophrenia follows a progressive decline over the years of evolution of the disease (a conclusion predominant in studies with cross-sectional methodology) and 2) Cognition in schizophrenia remains stable once it appears during the first stages of the disease (a conclusion predominant in longitudinal studies). The authors conclude that the question about the likely decline of cognition in schizophrenia cannot be answered due to the lack of rigorous and thorough follow-up studies (AU)

[Evidence of the effectiveness of cognitive rehabilitation in psychosis and schizophrenia with the REHACOP programme]. / Evidencias de eficacia de la rehabilitación cognitiva en psicosis y esquizofrenia con el programa REHACOP.

INTRODUCTION: Neuropsychological rehabilitation in schizophrenia is a recent development and few studies have been conducted to determine its effectiveness in samples of a Spanish population. Specific therapeutic programmes have recently been designed, like REHACOP, which is a programme of cognitive rehabilitation in psychosis. This study aims to test the effectiveness of REHACOP in samples of patients with schizophrenia in a Spanish population in different phases of the disease. PATIENTS AND METHODS: Seventy-six patients were recruited and randomly assigned to either an experimental REHACOP group or a control group. The REHACOP group took part in three structured sessions held weekly for a period of three months, while the control group attended occupational therapy sessions with the same frequency and intensity. Both groups received standard additional treatment according to their course and progress. All the patients were evaluated before and after the intervention on attention, language, learning and memory, processing speed and executive functions. RESULTS: The REHACOP group offered significant improvements, with respect to the control group, in all the cognitive functions that were explored including attention, visuomotor integration, learning and memory or executive functions. Likewise, the REHACOP group showed a significant clinical and emotional improvement compared to the control group, as well as additional gains in their capacity for insight into the disease. CONCLUSIONS: The data from this study suggest that REHACOP can be an effective programme of intervention for bringing about improvements in the neuropsychological deterioration of patients with schizophrenia, regardless of the degree of impairment and the stage of progress of the disease.

Evidencias de eficacia de la rehabilitación cognitiva en psicosis y esquizofrenia con el programa REHACOP / Evidence of the effectiveness of cognitive rehabilitation in psychosis and schizophrenia with the REHACOP programme

Introducción. La rehabilitación neuropsicológica en esquizofrenia tiene un recorrido reciente y su eficacia en muestras depoblación española se ha comprobado en escasas ocasiones. Recientemente se han diseñado programas terapéuticos específicos,como el REHACOP, programa de rehabilitación cognitiva en psicosis. El objetivo de este estudio es probar la eficacia del REHACOP en muestras de pacientes con esquizofrenia en población española en diferentes fases de la enfermedad. Pacientes y métodos. Se reclutaron 76 pacientes que fueron asignados aleatoriamente a un grupo experimental REHACOP o a un grupo control. El grupo REHACOP realizó tres sesiones estructuradas semanales durante tres meses, mientras que el grupo control acudió a sesiones de terapia ocupacional con la misma frecuencia e intensidad. Ambos grupos recibieron el tratamiento adicional estándar en función de su curso y evolución. Se evaluó a todos los pacientes antes y después dela intervención en atención, lenguaje, aprendizaje y memoria, velocidad de procesamiento y funciones ejecutivas. Resultados. El grupo REHACOP presentó mejorías significativas en todas las funciones cognitivas exploradas respecto algrupo control, incluyendo atención, integración visuomotora, aprendizaje y memoria o funciones ejecutivas. Asimismo, el grupo REHACOP mostró una mejoría clínica y emocional significativa respecto al grupo control y ganancias adicionales en su capacidad de insight sobre la enfermedad. Conclusión. Los datos de este estudio sugieren que el REHACOP puede ser un programa de intervención eficaz para inducirmejoras en el deterioro neuropsicológico en pacientes con esquizofrenia independientemente del grado de deterioro y del estado evolutivo de la enfermedad (AU)

Introduction. Neuropsychological rehabilitation in schizophrenia is a recent development and few studies have been conducted to determine its effectiveness in samples of a Spanish population. Specific therapeutic programmes have recently been designed, like REHACOP, which is a programme of cognitive rehabilitation in psychosis. This study aims to test the effectiveness of REHACOP in samples of patients with schizophrenia in a Spanish population in different phases of the disease.Patients and methods. Seventy-six patients were recruited and randomly assigned to either an experimental REHACOPgroup or a control group. The REHACOP group took part in three structured sessions held weekly for a period of three months, while the control group attended occupational therapy sessions with the same frequency and intensity. Bothgroups received standard additional treatment according to their course and progress. All the patients were evaluated before and after the intervention on attention, language, learning and memory, processing speed and executive functions.Results. The REHACOP group offered significant improvements, with respect to the control group, in all the cognitive functions that were explored including attention, visuomotor integration, learning and memory or executive functions.Likewise, the REHACOP group showed a significant clinical and emotional improvement compared to the control group, as well as additional gains in their capacity for insight into the disease. Conclusions. The data from this study suggest that REHACOP can be an effective programme of intervention for bringing about improvements in the neuropsychological deterioration of patients with schizophrenia, regardless of the degree ofimpairment and the stage of progress of the disease (AU)

[REHACOP: a cognitive rehabilitation programme in psychosis]. / REHACOP: programa de rehabilitacion cognitiva en psicosis.

INTRODUCTION: In this work we present REHACOP, a programme of cognitive rehabilitation in psychosis. MATERIALS AND METHODS: The foundation of the REHACOP programme (its structure, materials, aims, work methodology and means of implementation) are described in detail. RESULTS AND CONCLUSIONS: This new therapeutic tool is presented with the aim of being of use to guide professionals who seek to design an intervention of this kind in samples of patients with schizophrenia or other pathologies.

REHACOP: programa de rehabilitación cognitiva en psicosis / REHACOP: a cognitive rehabilitation programme in psychosis

Introducción. En el presente trabajo se presenta el programa REHACOP, programa de rehabilitación cognitiva en psicosis. Materiales y métodos. La fundamentación del programa REHACOP -su estructura, materiales, objetivos, metodología de trabajo y modos de implementación- se describe de modo detallado. Resultados y conclusiones. Se ofrece una nueva herramienta terapéutica con el objetivo de que pueda servir de orientación a profesionales que se planteen el diseño de una intervención de estas características en muestras de pacientes con esquizofrenia u otras patologías (AU)

Introduction. In this work we present REHACOP, a programme of cognitive rehabilitation in psychosis. Materials and methods. The foundation of the REHACOP programme (its structure, materials, aims, work methodology and means of implementation) are described in detail. Results and conclusions. This new therapeutic tool is presented with the aim of being of use to guide professionals who seek to design an intervention of this kind in samples of patients with schizophrenia or other pathologies (AU)

An explanatory model of quality of life in schizophrenia: the role of processing speed and negative symptoms.

INTRODUCTION: Improving the quality of life of patients with schizophrenia is a major goal in managing this devastating disorder, but agreement is lacking about the factors that predict quality of life (QoL) over the course of the disorder. METHODS: We examined 165 hospitalized patients with schizophrenia in this study. We included measures for psychiatric (PANSS, insight and affective symptoms) and cognitive symptoms. Confirmatory factor analysis established a cognitive structure composed of the following six factors: attention, processing speed, verbal memory, fluency, working memory and executive functioning. Quality of life was assessed using the Heinrichs-Hanlon-Carpenter Scale. RESULTS: Age, duration of illness, presence of more severe negative symptoms and most cognitive factors correlated significantly with QoL indicators. Regression analysis showed that processing speed (PS) was by far the most important cognitive factor that predicted QoL. Moreover, the interaction between PS and negative symptoms, patient age and executive functions modified the effect of PS on QoL. Finally, positive symptoms and other socio-demographic data were not related to QoL in the current study. CONCLUSIONS: Our findings suggest that PS and negative symptoms predict QoL in schizophrenia.

Un modelo explicativo de la calidad de vida en la esquizofrenia: el papel de la velocidad de procesamiento y los síntomas negativos / An explanatory model of quality of life in schizophrenia: the role of processing speed and negative symptoms

Introducción. Mejorar la calidad de vida de los pacientes con esquizofrenia es un objetivo fundamental en una enfermedad que resulta devastadora, pero no hay acuerdo sobre qué factores predicen la calidad de vida (CV) en el curso de la enfermedad. Metodología. En el presente estudio se examinaron a165 pacientes hospitalizados con esquizofrenia. Se incluyeron medidas de síntomas psiquiátricos (PANSS, insight y síntomas afectivos) y cognitivas. Un análisis factorial confirmatorio estableció una estructura cognitiva compuesta de seis factores, que incluyen atención, velocidad de procesamiento, memoria verbal, fluidez, memoria de trabajo y funciones ejecutivas. La calidad de vida fue medida mediante la Escala de Calidad de Vida de Heinrichs-Hanlon-Carpenter. Resultados. La edad, tiempo de duración de la enfermedad, mayor gravedad de síntomas negativos y la mayoría de factores cognitivos correlacionaron significativamente con los indicadores de CV. Los análisis de regresión mostraron que, muy por encima de los demás factores cognitivos, la velocidad de procesamiento (VP) es un importante predictor de la CV. Además, la interacción de la VP con los síntomas negativos, la edad del paciente y el nivel de deterioro en funciones ejecutivas modificaron el efecto de la VP sobre la CV. Finalmente, los síntomas positivos y otros datos sociodemográficos no guardaron relación con la CV en nuestro estudio. Conclusiones. Nuestros hallazgos sugieren que la VP y los síntomas negativos predicen la CV en la esquizofrenia (AU)

Introduction. Improving the quality of life of patients with schizophrenia is a major goal in managing this devastating disorder, but agreement is lacking about the factors that predict quality of life (QoL) over the course of the disorder. Methods. We examined 165 hospitalized patients with schizophrenia in this study. We included measures for psychiatric (PANSS, insight and affective symptoms) and cognitive symptoms. Confirmatory factor analysis established a cognitive structure composed of the following six factors: attention, processing speed, verbal memory, fluency, working memory and executive functioning. Quality of life was assessed using the Heinrichs-Hanlon-Carpenter Scale. Results. Age, duration of illness, presence of more severe negative symptoms and most cognitive factors correlated significantly with QoL indicators. Regression analysis showed that processing speed (PS) was by far the most important cognitive factor that predicted QoL. Moreover, the interaction between PS and negative symptoms, patient age and executive functions modified the effect of PS on QoL. Finally, positive symptoms and other socio-demographic data were not related to QoL in the current study. Conclusions. Our findings suggest that PS and negative symptoms predict QoL in schizophrenia (AU)

Verbal fluency in schizophrenia: does cognitive performance reflect the same underlying mechanisms in patients and healthy controls?

Verbal fluency is impaired in patients with schizophrenia, but the association with other cognitive domains remains unclear. Forty-seven patients with schizophrenia (DSM-IV) and 47 controls matched by age, gender, years of education, and vocabulary (Wechsler Adult Intelligence Scale-III) were assessed in terms of sociodemographic, clinical, and cognitive variables. Healthy controls performed significantly better than patients with schizophrenia in all cognitive measures. However, the way these cognitive domains were related differed across groups. Semantic fluency (SF) and phonological fluency (PF) were predicted by working memory (WM) in patients with schizophrenia, whereas the predictor in the healthy controls was processing speed (PS). Moreover, after dividing the sample of patients according to their performance on fluency tests, we found that a worse performance on SF or PF was predicted by WM. However, for patients with a better performance on fluency, the pattern was similar to that of healthy controls. Cognition may show a different pattern of interaction in schizophrenia, with less impaired patients showing a closer pattern to healthy controls. Therefore, we suggest that, depending on the severity of cognitive deficits, performance on neuropsychological tests may not reflect the same underlying mechanisms.

[Attention deficits and response to drug therapy in patients with treatment-resistant schizophrenia: results through confirmatory factor analysis]. / Déficit atencionales y respuesta al tratamiento farmacológico en pacientes con esquizofrenia resistente al tratamiento: Resultados mediante análisis factorial confirmatorio.

INTRODUCTION: There are no experimental data that demonstrate whether patients with neuroleptic-resistant schizophrenia differ or not in their pattern of neuropsychological functioning from patients with adequate drug response. METHOD: Fifty-two patients with drug-resistant psychosis (DRP) and 42 patients with schizophrenia not resistant to treatment (NDRP) were recruited following the criteria of Kane et al (1988). A sample of 45 healthy controls matched by age, sex and educational level was also recruited. The clinical evaluations used were the Positive and Negative Symptom Scale (PANSS), functional disability (WHO-DAS) and the Clinical Global Impression (CGI) scale. RESULTS: Through the use of confirmatory factor analysis, we obtained a latent cognitive structure of six cognitive factors: attention, processing speed, verbal memory, working memory, verbal fluency and executive functions. As expected, the control group performed better than the two patient groups (both DRP and NDRP) in all neuropsychological domains. Additionally, the DRP group scored significantly worse in attention than the NDRP group even though no differences between these two groups were found in age of disease onset, number of hospitalizations or length of hospitalization. From a clinical point of view, the DRP group showed greater severity of positive symptoms (p<0.01) and higher global deterioration (p<0.01), which did not translate into greater functional disability. CONCLUSIONS: The results obtained do not allow us to conclude that there is a specific neuropsychological profile in neuroleptic-resistant patients. The only differential parameter was performance in the attentional domain. Our findings better fit the hypothesis of a «clinical continuum¼ and differ from the categoric classification of this mental disorder.

Predictors of longitudinal changes in schizophrenia: the role of processing speed.

BACKGROUND: The main objective was to identify variables that predict functional disability in chronic schizophrenia over time. METHOD: We examined 95 hospitalized patients with schizophrenia (DSM-IV criteria) in a long-stage unit and 53 healthy controls (matched for age, gender, and years of education). Neuropsychological battery included tests for verbal memory, working memory, executive functioning, and processing speed. Functional disability was assessed at 6-month follow-up with the Disability Assessment Schedule after the neuropsychological and clinical assessment. The study was conducted from September 2005 to July 2008. RESULTS: Patient performance was significantly lower than that of the healthy comparison subjects on all neurocognitive variables (p < .001). Most, but not all, neurocognitive measures were significantly correlated with the patients' functional disability shown 6 months after admission to the study, including self-care management, vocational outcome, family contact, and social functioning. Results suggest that processing speed has a significant influence in these relationships. CONCLUSIONS: Processing speed plays an outstanding role in the relationship between neurocognitive symptoms and self-care, vocational outcome, and social functioning. Our data support the possibility of processing speed as the best longitudinal predictor of the level of autonomy in patients with chronic schizophrenia.

Cognitive performance and cigarette smoking in first-episode psychosis.

The purpose of this study is to describe possible differences in cognitive functioning between smoking and non-smoking patients with first-episode psychosis and to determine whether there is a better cognitive profile associated with smoking. We assessed 61 first-episode psychosis patients with a neuropsychological battery that included computerized measurements of attention, working memory, and executive functioning. Patients were grouped into two categories: non-smokers (0 cigarettes/day; n = 30) and smokers (>/=20 cigarettes/day; n = 31). No significant differences were detected in sociodemographic and clinical data between the two groups. For attention tasks, smokers exhibited shorter reaction times in the sustained attention test than non-smokers (P = 0.039) and needed less time to complete the Stroop interference test (P = 0.013). In the working memory task, smokers exhibited shorter reaction times (P = 0.029) and presented a significantly lower percentage of omission (P = 0.002) and commission errors (P = 0.020) than non-smokers. For executive functioning, no differences were detected between groups in performance on the Wisconsin Card Sorting Test. Results indicate that first-episode psychosis patients who are nicotine users have better cognitive functioning in the areas of attention and working memory than patients who are not nicotine users. This study supports the cognitive approach to the self-medication hypothesis, to explain the high rates of cigarette smoking among psychosis patients. These results may be relevant for developing new strategies involving nicotinic receptors for cognitive enhancement in psychosis.

Processing speed mediates the relationship between verbal memory, verbal fluency, and functional outcome in chronic schizophrenia.

Verbal fluency and verbal memory have been reported to be diminished in patients with schizophrenia. These deficits could partially predict functional disability in this pathology. However, processing speed often mediates the relationship among cognitive processes in the disorder. Our goal was to analyse the influence of processing speed as mediator of the relation between verbal fluency-verbal memory and functional disability in chronic schizophrenia. We examined 90 hospitalized patients and 30 healthy controls (matched for gender, age and years of education). The neuropsychological battery included tests for verbal fluency, verbal memory, motor speed and processing speed. Outcome measures included Disability Assessment Schedule (DAS-WHO) and number of hospitalizations (NH). Results confirmed chronicity on clinical symptoms (PANSS total X=48.94+14.97 PANSS negative X=27.81+10.18, PANSS positive X=23.51+10.81) and impairment on functional disability (DAS-WHO X=13.62+4.28). As expected, verbal fluency was severely impaired in patients and significantly predicted functional outcome. Immediate and Delayed Verbal Memory were also severely impaired and predicted functional outcome. However, when processing speed was entered in the regression analyses the significance of verbal fluency and verbal memory decreased significantly. Sobel's equation was significant, suggesting full mediation. Our findings suggest that processing speed may be a central factor in the relation between cognitive symptoms and functional outcome in chronic schizophrenia.

Course of cognitive functioning in first-episode psychosis: a comparison between schizophrenia and non schizophrenia psychosis.

AIMS: To describe the course of cognitive functioning in first-episode psychosis and to determine possible differences in the degree and trajectory of cognitive deficits between schizophrenia and non-schizophrenia first-episode psychosis. METHOD: We assessed attention, working memory, and executive functioning in 57 patients with first-episode psychosis both at baseline and at 1-year of follow-up. RESULTS: For the overall group, significant reductions were found in the percentage of omission and commission errors for the sustained attention task (p<0.001 and p=0.001, respectively), in the total time to complete the Stroop-I task (p<0.001), in the percentage of omission errors for the working memory task (p=0.001), and in the percentage of perseverative errors for the Wisconsin card sorting test (WCST; p<0.001), as well as a significant increase in the number of categories completed in the WCST (p<0.001). The remaining cognitive variables analyzed remained stable (4 of the 10 variables tested). The pattern of change was similar for patients with schizophrenia (n=20) and non-schizophrenia (n=37) in the areas of attention and working memory. For executive functioning, the non-schizophrenia group showed a more beneficial pattern of change. No significant differences were detected in cognitive performance among subgroups at baseline or at the 1-year follow-up. CONCLUSION: The course of cognitive deficits in first-episode psychosis showed significant improvements over the 1-year period in the areas of attention, working memory and executive functioning. Neuropsychological performance did not seem to be specific enough to distinguish between patients with schizophrenia and non-schizophrenia first-episode psychosis, at least during the first year.