11 resultados para Schizophrenia, Smoking, Antipsychotic
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
The onset and early course of schizophrenia is associated with subtle loss of grey matter which may be responsible for the evolution and persistence of symptoms such as apathy, emotional blunting, and social withdrawal. Such 'negative' symptoms are unaffected by current antipsychotic therapies. There is evidence that the antibiotic minocycline has neuroprotective properties. We investigated whether the addition of minocycline to treatment as usual (TAU) for 1 year in early psychosis would reduce negative symptoms compared with placebo. In total, 144 participants within 5 years of first onset in Brazil and Pakistan were randomised to receive TAU plus placebo or minocycline. The primary outcome measures were the negative and positive syndrome ratings using the Positive and Negative Syndrome Scale. Some 94 patients completed the trial. The mean improvement in negative symptoms for the minocycline group was 9.2 and in the placebo group 4.7, an adjusted difference of 3.53 (s.e. 1.01) 95% CI: 1.55, 5.51; p < 0.001 in the intention-to-treat population. The effect was present in both countries. The addition of minocycline to TAU early in the course of schizophrenia predominantly improves negative symptoms. Whether this is mediated by neuroprotective, anti-inflammatory or others actions is under investigation.
Resumo:
These updated guidelines are based on a first edition of the World Federation of Societies of Biological Psychiatry Guidelines for Biological Treatment of Schizophrenia published in 2005. For this 2012 revision, all available publications pertaining to the biological treatment of schizophrenia were reviewed systematically to allow for an evidence-based update. These guidelines provide evidence-based practice recommendations that are clinically and scientifically meaningful and these guidelines are intended to be used by all physicians diagnosing and treating people suffering from schizophrenia. Based on the first version of these guidelines, a systematic review of the MEDLINE/PUBMED database and the Cochrane Library, in addition to data extraction from national treatment guidelines, has been performed for this update. The identified literature was evaluated with respect to the strength of evidence for its efficacy and then categorised into six levels of evidence (A-F; Bandelow et al. 2008b, World J Biol Psychiatry 9: 242). This first part of the updated guidelines covers the general descriptions of antipsychotics and their side effects, the biological treatment of acute schizophrenia and the management of treatment-resistant schizophrenia.
Resumo:
Background: Stigmatization is an important issue in the treatment and course of schizophrenia. The maintenance of stigmatizing attitudes may be related to socio-cultural factors. Objectives: To compare stigmatizing attitudes of mental health professionals in the culturally diverse countries Brazil and Switzerland. Methods: We analyzed data of two broad stigmatization surveys from Switzerland and Brazil by focusing on the social distance and attitudes of mental health professionals towards the acceptance of side effects of psychopharmacological treatment. Results: Swiss mental health professionals showed significantly higher levels of social distance than their Brazilian counterparts. There was also a weak effect of age as well as an interaction effect between origin and age. With respect to the acceptance of side effects, the effect of origin was rather weak. With the exception of drug dependence, Swiss professionals' acceptance of long-lasting side effects was significantly higher than for their counterparts in Brazil. Discussion: The strong association between origin and social distance may be related to the socio-cultural background of the mental health professionals. In comparison with Switzerland, Brazil is very heterogeneous in terms of ethnicity and socio-economic structure. The distinct acceptance of side effects may additionally be related to the more sophisticated medicaments (i.e. new generation of antipsychotic drugs) commonly used in Switzerland. Hengartner MP, et al. / Rev Psiq Clin. 2012;39(4):115-21
Resumo:
Second generation antipsychotics (SGAs) have been linked to metabolic and bone disorders in clinical studies, but the mechanisms of these side effects remain unclear. Additionally, no studies have examined whether SGAs cause bone loss in mice. Using in vivo and in vitro modeling we examined the effects of risperidone, the most commonly prescribed SGA, on bone in C57BL6/J (B6) mice. Mice were treated with risperidone orally by food supplementation at a dose of 1.25 mg/kg daily for 5 and 8 weeks, starting at 3.5 weeks of age. Risperidone reduced trabecular BV/TV, trabecular number and percent cortical area. Trabecular histomorphometry demonstrated increased resorption parameters, with no change in osteoblast number or function. Risperidone also altered adipose tissue distribution such that white adipose tissue mass was reduced and liver had significantly higher lipid infiltration. Next, in order to tightly control risperidone exposure, we administered risperidone by chronic subcutaneous infusion with osmotic minipumps (0.5 mg/kg daily for 4 weeks) in 7 week old female B6 mice. Similar trabecular and cortical bone differences were observed compared to the orally treated groups (reduced trabecular BV/TV, and connectivity density, and reduced percent cortical area) with no change in body mass, percent body fat, glucose tolerance or insulin sensitivity. Unlike in orally treated mice, risperidone infusion reduced bone formation parameters (serum P1NP, MAR and BFR/BV). Resorption parameters were elevated, but this increase did not reach statistical significance. To determine if risperidone could directly affect bone cells, primary bone marrow cells were cultured with osteoclast or osteoblast differentiation media. Risperidone was added to culture medium in clinically relevant doses of 0, 2.5 or 25 ng/ml. The number of osteoclasts was significantly increased by addition in vitro of risperidone while osteoblast differentiation was not altered. These studies indicate that risperidone treatment can have negative skeletal consequences by direct activation of osteoclast activity and by indirect non-cell autonomous mechanisms. Our findings further support the tenet that the negative side effects of SGAs on bone mass should be considered when weighing potential risks and benefits, especially in children and adolescents who have not yet reached peak bone mass. This article is part of a Special Issue entitled: Interactions Between Bone, Adipose Tissue and Metabolism. (C) 2011 Elsevier Inc. All rights reserved.
Resumo:
For the last 40 years, schizophrenia has been considered to be the result primarily of a dysfunction in brain dopaminergic pathways. In this review, it is described and discussed findings concerning nitric oxide-mediated neurotransmission in schizophrenia. Studies were searched in PubMed, SciELO, and LILACS using the terms schizophrenia and nitric oxide plasma levels or nitric oxide serum levels, with no time limit. The reference lists of selected articles were also hand-searched for additional articles. From 15 potential reports, 10 were eligible to be included in the review and meta-analysis. These studies included a total of 505 patients with schizophrenia and 339 healthy volunteers. No significant difference was found between patients and healthy controls regarding total nitrite plasma/serum levels (effect size g = 0.285, 95%CI = -0.205 to 0.774, p = 0.254). However, when studies with patients under antipsychotic treatment were examined separately, there was a significant difference between patients and healthy volunteers (effect size g = 0.663, 95%CI = 0.365 to 0.961, p < 0.001), showing that patients under treatment have higher levels of plasma/serum nitric oxide than controls. These results suggest that antipsychotics increase nitric oxide plasma/serum levels and that the nitrergic pathway would be a fertile target for the development of new treatments for patients with schizophrenia.
Resumo:
Smoking cue-provoked craving is an intricate behavior associated with strong changes in neural networks. Craving is one of the main reasons subjects continue to smoke; therefore interventions that can modify activity in neural networks associated with craving can be useful tools in future research investigating novel treatments for smoking cessation. The goal of this study was to use a neuromodulatory technique associated with a powerful effect on spontaneous neuronal firing - transcranial direct current stimulation (tDCS) - to modify cue-provoked smoking craving. Based on preliminary data showing that craving can be modified after a single tDCS session, here we investigated the effects of repeated tDCS sessions on craving behavior. Twenty-seven subjects were randomized to receive sham or active tDCS (anodal tDCS of the left DLPFC). Our results show a significant cumulative effect of tDCS on modifying smoking cue-provoked craving. In fact, in the group of active stimulation, smoking cues had an opposite effect on craving after stimulation - it decreased craving - as compared to sham stimulation in which there was a small decrease or increase on craving. In addition, during these 5 days of stimulation there was a small but significant decrease in the number of cigarettes smoked in the active as compared to sham tDCS group. Our findings extend the results of our previous study as they confirm the notion that tDCS has a specific effect on craving behavior and that the effects of several sessions can increase the magnitude of its effect. These results open avenues for the exploration of this method as a therapeutic alternative for smoking cessation and also as a mean to change stimulus-induced behavior. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
Resumo:
This paper aims to discuss and test the hypothesis raised by Fusar-Poli [Fusar-Poli P. Can neuroimaging prove that schizophrenia is a brain disease? A radical hypothesis. Medical Hypotheses in press, corrected proof] that ""on the basis of the available imaging literature there is no consistent evidence to reject the radical and provocative hypothesis that schizophrenia is not a brain disease"". To achieve this goal, all meta-analyses on `fMRI and schizophrenia` published during the current decade and indexed in Pubmed were summarized, as much as some other useful information, e.g., meta-analyses on genetic risk factors. Our main conclusion is that the literature fully supports the hypothesis that schizophrenia is a syndrome (not a disease) associated with brain abnormalities, despite the fact that there is no singular and reductionist pathway from the nosographic entity (schizophrenia) to its causes. This irreducibility is due to the fact that the syndrome has more than one dimension (e.g., cognitive, psychotic and negative) and each of them is related to abnormalities in specific neuronal networks. A psychiatric diagnosis is a statistical procedure; these dimensions are not identically represented in each diagnosticated case and this explains the existence of more than one pattern of brain abnormalities related to schizophrenia. For example, chronification is associated with negativism while the first psychotic episode is not; in that sense, the same person living with schizophrenia may reveal different symptoms and fMRI patterns along the course of his life, and this is precisely what defines schizophrenia since the time when it was called Dementia Praecox (first by pick then by Kraepelin). It is notable that 100% of the collected meta-analyses on `fMRI and schizophrenia` reveal positive findings. Moreover, all meta-analyses that found positive associations between schizophrenia and genetic risk factors have to do with genes (SNPs) especially activated in neuronal tissue of the central nervous system (CNS), suggesting that, to the extent these polymorphisms are related to schizophrenia`s etiology, they are also related to abnormal brain activity. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
Inaccurate wiring and synaptic pathology appear to be major hallmarks of schizophrenia. A variety of gene products involved in synaptic neurotransmission and receptor signaling are differentially expressed in brains of schizophrenia patients. However, synaptic pathology may also develop by improper expression of intra- and extra-cellular structural elements weakening synaptic stability. Therefore, we have investigated transcription of these elements in the left superior temporal gyrus of 10 schizophrenia patients and 10 healthy controls by genome-wide microarrays (Illumina). Fourteen up-regulated and 22 downregulated genes encoding structural elements were chosen from the lists of differentially regulated genes for further qRT-PCR analysis. Almost all genes confirmed by this method were downregulated. Their gene products belonged to vesicle-associated proteins, that is, synaptotagmin 6 and syntaxin 12, to cytoskeletal proteins, like myosin 6, pleckstrin, or to proteins of the extracellular matrix, such as collagens, or laminin C3. Our results underline the pivotal roles of structural genes that control formation and stabilization of pre- and post-synaptic elements or influence axon guidance in schizophrenia. The glial origin of collagen or laminin highlights the close interrelationship between neurons and glial cells in establishment and maintenance of synaptic strength and plasticity. It is hypothesized that abnormal expression of these and related genes has a major impact on the pathophysiology of schizophrenia.
Resumo:
Background: schizophrenia's endophenotipic profile is not only generally complex, but often varies from case to case. The perspective of trying to define specific anatomic correlates of the syndrome has led to disappointing results. In that context, neurophysiologic hypotheses (e. g. glutamatergic hypothesis) and connectivity hypotheses became prominent. Nevertheless, despite their commitment to the principle of denying 'localist' views and approaching the syndrome's endophenotype from a whole brain perspective, efforts to integrate both have not flourished at this moment in time. Objectives: This paper aims to introduce a new etiological model that integrates the glutamatergic and the WM (WM) hypotheses of schizophrenia's etiology. This model proposes to serve as a framework in order to relate to patterns of brain abnormalities from the onset of the syndrome to stages of advanced chronification. Highlights: Neurotransmitter abnormalities forego noticeable WM abnormalities. The former, chiefly represented by NMDAR hypo-function and associated molecular cascades, is related to the first signs of cell loss. This process is both directly and indirectly integrated to the underpinning of WM structural abnormalities; not only is the excess of glutamate toxic to the WM, but its disruption is associated to the expression of known genetic risk factors (e. g., NRG-1). A second level of the model develops the idea that abnormal neurotransmission within specific neural populations ('motifs') impair particular cognitive abilities, while subsequent WM structural abnormalities impair the integration of brain functions and multimodality. As a result of this two-stage dynamic, the affected individual progresses from experiencing specific cognitive and psychological deficits, to a condition of cognitive and existential fragmentation, linked to hardly reversible decreases in psychosocial functioning.
Resumo:
Recent findings in the literature suggest a relation between histidine triad nucleotide-binding protein-1 (HINT1) and psychiatric disorders such as major depression, anxiety, and schizophrenia, although its physiological roles are not completely comprehended. Using Western blot, we compared HINT1 protein expression in the postmortem dorsolateral prefrontal cortex and thalamus of schizophrenia patients and healthy controls for contributing to elucidate the role of HINT1 in schizophrenia pathophysiology. HINT1 was found to be downregulated in the dorsolateral prefrontal cortex and upregulated in the thalamus. Our results combined to previous studies in human samples and preclinical models support the notion that HINT1 must be more explored as a potential target for psychiatric disorders.
Resumo:
Schizophrenia is a severe psychiatric disorder with frequent recurrent psychotic relapses and progressive functional impairment. It results from a poorly understood gene-environment interaction. The gene encoding catechol-O-methyltransferase (COMT) is a likely candidate for schizophrenia. Its rs165599 (A/G) polymorphism has been shown to be associated with alteration of COMT gene expression. Therefore, the present study aimed to investigate a possible association between schizophrenia and this polymorphism. The distribution of the alleles and genotypes of this polymorphism was investigated in a Brazilian sample of 245 patients and 834 controls. The genotypic frequencies were in Hardy-Weinberg equilibrium and no statistically significant differences were found between cases and controls when analyzed according to gender or schizophrenia subtypes. There was also no difference in homozygosis between cases and controls. Thus, in the sample studied, there was no evidence of any association between schizophrenia and rs165599 (A/G) polymorphism in the non-coding region 3' of the COMT gene.