Biomedical subjects

Roberta Rasetti

Publications and source records attributed to Roberta Rasetti.

7 recordsLinked to original sources

PubMed2006

Neuropsychological correlates of reality distortion in schizophrenic patients.

The present study aims at exploring the relationship between content-related aspects of delusions and hallucinations in schizophrenia and the basic domains of cognition, controlling for the other clinical and demographic variables that could produce bias in the interpretation of the results. Seventy stable schizophrenic patients were evaluated through psychiatric assessment and a neuropsychological battery including tests on attention, memory, perceptual-motor speed and executive functions. We found that the severity of negative symptoms was strongly correlated with poor performance in almost all domains of cognitive functions, while only the attentional deficit was correlated with positive symptoms. The relationships between different cognitive domains and specific types of delusions and hallucinations showed that thought insertion, guilt, grandiose, religious and somatic delusions were associated with impairment in different cognitive functions (verbal and visual memory, attention and executive functions). Voices arguing and tactile hallucinations were correlated to delay-recall memory function. Our results suggest that no specific cognitive pattern is associated with typical-content delusions and hallucinations. On the basis of our findings, cognitive impairments associated with delusions and hallucinations, as measured by our battery, seem not to play a central role in the genesis and the maintenance of these symptoms, suggesting a more complex model of pathogenesis.

Adult↗

PubMed2006

Tolcapone improves cognition and cortical information processing in normal human subjects.

Prefrontal cortical dopamine (DA) regulates various executive cognitive functions, including attention and working memory. Efforts to enhance prefrontal-related cognition, which have focused on catecholaminergic stimulant drugs, have been unsatisfactory. Recently, the demonstration that a functional polymorphism in the catecholamine-O-methyltransferase (COMT) gene impacts prefrontal cognition raises the possibility of a novel pharmacological approach for the treatment of prefrontal lobe executive dysfunction. To explore in a proof of concept study the effects of tolcapone, a CNS penetrant specific COMT inhibitor, we performed a randomized, double blind, placebo controlled, and crossover design of this drug in normal subjects stratified by COMT (val158met) genotype. COMT enzyme activity was determined in peripheral blood. Forty-seven normal volunteers with no family history of psychiatric disorders underwent neuropsychological testing and 34 of those subjects underwent physiological measurement of prefrontal information processing assessed by blood oxygen level-dependent functional magnetic resonance imaging (fMRI). We found significant drug effects on measures of executive function and verbal episodic memory and a significant drug by genotype interaction on the latter, such that individuals with val/val genotypes improved, whereas individuals with met/met genotypes worsened on tolcapone. fMRI revealed a significant tolcapone-induced improvement in the efficiency of information processing in prefrontal cortex during a working memory test. This study demonstrates enhancement of prefrontal cortical function in normal human subjects with a nonstimulant drug having COMT inhibitory activity. Our results are consistent with data from animal studies and from computational models of the effects of selective enhancement of DA signaling in the prefrontal cortex.

Adult↗

PubMed2005

Spontaneous electrical activity and dendritic spine size in mature cerebellar Purkinje cells.

Previous experiments have shown that in the mature cerebellum both blocking of spontaneous electrical activity and destruction of the climbing fibres by a lesion of the inferior olive have a similar profound effect on the spine distribution on the proximal dendrites of the Purkinje cells. Many new spines develop that are largely innervated by parallel fibers. Here we show that blocking electrical activity leads to a significant decrease in size of the spines on the branchlets. We have also compared the size of the spines of the proximal dendritic domain that appear during activity block and after an inferior olive lesion. In this region also, the spines in the absence of activity are significantly smaller. In the proximal dendritic domain, the new spines that develop in the absence of activity are innervated by parallel fibers and are not significantly different in size from those of the branchlets, although they are shorter. Thus, the spontaneous activity of the cerebellar cortex is necessary not only to maintain the physiological spine distribution profile in the Purkinje cell dendritic tree, but also acts as a signal that prevents spines from shrinking.

Action Potentials↗

PubMed2004

Relationships of age at onset with clinical features and cognitive functions in a sample of schizophrenia patients.

BACKGROUND: A number of studies investigated the relationships of age at onset with clinical presentation and cognitive performance of schizophrenic patients. The aim of the present study was to assess demographic and clinical characteristics; psychopathologic, social functioning, and quality-of-life ratings; and neuropsychological measures in a sample of patients with stabilized schizophrenia and to identify which factors independently contributed to a multiple regression model with age at onset as the dependent variable. METHOD: Ninety-six consecutive outpatients with schizophrenia (DSM-IV-TR criteria) were included in the study. Assessment instruments were as follows: a semistructured interview, the Clinical Global Impressions scale, the Comprehensive Psychopathological Rating Scale, and the Positive and Negative Syndrome Scale (PANSS) for psycho-pathology of schizophrenia; the Calgary Depression Scale for Schizophrenia (CDSS) for depression; the Social and Occupational Functioning Assessment Scale and the Sheehan Disability Scale for social functioning; the Quality of Life Scale; and a neuro-psychological battery including the Wisconsin Card Sorting Test (WCST) and the Continuous Performance Test. Two models of multiple regression were tested: the first included clinical features and psychopathologic, social functioning, and quality-of-life scales; the second also considered neuro-psychological variables. Data were collected from October 2001 to November 2002. RESULTS: The first multiple regression showed that age at onset was significantly related to scores on the PANSS subscale for negative symptoms (p =.042) and the CDSS (p =.041); the second regression found a relation of age at onset with PANSS score for negative symptoms (p =.002) and 2 neuropsychological measures, number of preservative errors on the WCST and Continuous Performance Test reaction time (p =.0005 for both). CONCLUSION: Our data indicate that, when results of neuropsychological tests are considered, early age at onset of schizophrenia is associated with severity of negative symptoms and compromised cognitive measures of executive functioning and sustained attention.

Adult↗

PubMed2003

Predictors of psychiatric disorders in liver transplantation candidates: logistic regression models.

This study has two goals. The first goal is to assess the prevalence of psychiatric disorders in orthotopic liver transplantation (OLT) candidates by means of standardized procedures because there has been little research concerning psychiatric problems of potential OLT candidates using standardized instruments. The second goal focuses on identifying predictors of these psychiatric disorders. One hundred sixty-five elective OLT candidates were assessed by our unit. Psychiatric diagnoses were based on the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Patients also were assessed using the Hamilton Depression Rating Scale (HDRS) and the Spielberger Anxiety Index, State and Trait forms (STAI-X1 and STAI-X2). Severity of cirrhosis was assessed by applying Child-Pugh score criteria. Chi-squared and general linear model analysis of variance were used to test the univariate association between patient characteristics and both clinical psychiatric diagnoses and severity of psychiatric diseases. Variables with P less than.10 in univariate analyses were included in multiple regression models. Forty-three percent of patients presented at least one psychiatric diagnosis. Child-Pugh score and previous psychiatric diagnoses were independent significant predictors of depressive disorders. Severity of psychiatric symptoms measured by psychometric scales (HDRS, STAI-X1, and STAI-X2) was associated with Child-Pugh score in the multiple regression model. Our data suggest a high rate of psychiatric disorders, particularly adjustment disorders, in our sample of OLT candidates. Severity of liver disease emerges as the most important variable in predicting severity of psychiatric disorders in these patients.

Adult↗

PubMed2002

A comparison of paroxetine versus paroxetine plus amisulpride in the treatment of dysthymic disorder: efficacy and psychosocial outcomes.

Dysthymic disorder is a chronic depressive condition with considerable psychosocial impairment. Even if DD patients respond to various antidepressant medications, there has been little systematic study on antidepressant-refractory DD. Only a few trials have evaluated the effects of treatment on psychosocial functioning of dysthymic patients. In this 3-month, open-label study, 60 outpatients with DSM-IV criteria for dysthymic disorder who failed to respond to 3-month treatment with paroxetine 20 mg/day were randomly assigned to treatment with paroxetine 40 mg/day or paroxetine 20 mg/day plus amisulpride 50 mg/day. The effects of the two treatments were assessed for both mood symptoms (21-item Hamilton Rating Scale for Depression, Montgomery-Asberg Depression Rating Scale, Clinical Global Impression, severity and improvement) and psychosocial outcomes (DSM-IV Global Assessment of Functioning, Social Adaptation Self-evaluation Scale). Analysis of variance on all rating scales showed that both treatments were effective over this observation period. Response and remission rates did not differ in the treatment groups. A significantly greater psychosocial improvement was observed in the group receiving combined treatment compared with patients receiving paroxetine alone. Both treatments appeared to be effective in our sample of dysthymic subjects. Combined treatment with paroxetine and amisulpride resulted in a better outcome in terms of social functioning.

Adult↗

PubMedDate not supplied

Depressive and negative symptoms in schizophrenia: different effects on clinical features.

OBJECTIVE: The primary aim of this study was to investigate whether depressive symptoms were significantly associated with functional outcome measures in a clinically stable group of outpatients with schizophrenia. We also analyzed whether depressive and negative symptoms presented different patterns of predictors. METHOD: Seventy-eight consecutive outpatients meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria for schizophrenia in the stable period were enrolled in this cross-sectional study. Assessment were performed using the Calgary Depression Scale for Schizophrenia, Positive and Negative Syndromes Scale (PANSS), Clinical Global Impression Scale-severity, Social and Occupational Functioning Assessment Scale, Sheehan Disability Scale, and Quality of Life Scale. A neuropsychologic battery including the vocabulary and block design subtests of the Wechsler Adult Intelligence Scale-Revised, Wechsler Memory Scale, Wisconsin Card Sorting Test, and Continuous Performance Test was also administered to the patients. Two multiple regressions were performed testing demographic and clinical factors, rating scales, and cognitive measures as independent variables and Calgary Depression Scale for Schizophrenia and PANSS-negative subscale scores as dependent variables. RESULTS: Four variables were predictors of depressive symptoms in our sample of schizophrenic patients: 2 outcome measures (Sheehan Disability Scale and Quality of Life Scale), gender, and Continuous Performance Test reaction time. Predictors of negative symptoms were the measures of severity of psychopathology (Clinical Global Impression Scale-severity and PANSS-general psychopathology subscale) and the cognitive tests Wechsler Adult Intelligence Scale-Revised block design and Wechsler Memory Scale. CONCLUSION: We found that depressive symptoms in schizophrenia are mainly a function of the level of social adjustment and quality of life, whereas negative symptoms constitute an indicator of severity of schizophrenia. The 2 symptom dimensions showed also distinct cognitive correlates.

Adult↗