Method of simulation and choice of factors in the analysis of principal components

Objetivo Existem vários critérios para a escolha do número de componentes a serem mantidos na análise de componentes principais. Esta escolha pode dar-se por critérios arbitrários (critério de Kaiser p.ex.) ou subjetivos (fatores interpretáveis). Apresenta-se o critério de simulação de Lébart e Dreyfus. Método É gerada uma matriz de números aleatórios, sendo realizada a análise de componentes principais a partir dessa matriz. Os componentes extraídos de um conjunto de dados como este representam um limite inferior que deve ser ultrapassado para que um componente possa ser selecionado. Utiliza-se como exemplo a análise de componentes principais da escala de Hamilton para a depressão (17 itens) numa amostra de 130 pacientes. Resultados e Conclusões O método de simulação é comparado com o método de Kaiser. É mostrado que o método de simulação mantém apenas os componentes clinicamente significativos ao contrário do método de Kaiser.Objective There are many methods to determine how many components should be retained in principal components analysis. This choice can be made on the basis of arbitrary (Kaiser) or subjective (Interpretable factors) criteria. This work presents the simulation criteria of Lébart e Dreyfus. The method create a matrix of randomized numbers and a principal component analysis is performed on the basis of this matrix. The components extracted from this data represent the cut off values. Those that exceed this cut off value should be retained. As an example, a principal component analysis is performed with the Hamilton depression rating scale (17 items) on a sample of 130 subjects. Results and Conclusion The Simulation method is compared with the Kaiser method and is shown that the Simulation method maintains the components clinically significant

Method of simulation and choice of factors in the analysis of principal components

Objetivo Existem vários critérios para a escolha do número de componentes a serem mantidos na análise de componentes principais. Esta escolha pode dar-se por critérios arbitrários (critério de Kaiser p.ex.) ou subjetivos (fatores interpretáveis). Apresenta-se o critério de simulação de Lébart e Dreyfus. Método É gerada uma matriz de números aleatórios, sendo realizada a análise de componentes principais a partir dessa matriz. Os componentes extraídos de um conjunto de dados como este representam um limite inferior que deve ser ultrapassado para que um componente possa ser selecionado. Utiliza-se como exemplo a análise de componentes principais da escala de Hamilton para a depressão (17 itens) numa amostra de 130 pacientes. Resultados e Conclusões O método de simulação é comparado com o método de Kaiser. É mostrado que o método de simulação mantém apenas os componentes clinicamente significativos ao contrário do método de Kaiser.Objective There are many methods to determine how many components should be retained in principal components analysis. This choice can be made on the basis of arbitrary (Kaiser) or subjective (Interpretable factors) criteria. This work presents the simulation criteria of Lébart e Dreyfus. The method create a matrix of randomized numbers and a principal component analysis is performed on the basis of this matrix. The components extracted from this data represent the cut off values. Those that exceed this cut off value should be retained. As an example, a principal component analysis is performed with the Hamilton depression rating scale (17 items) on a sample of 130 subjects. Results and Conclusion The Simulation method is compared with the Kaiser method and is shown that the Simulation method maintains the components clinically significant

A Scale to Measure Subjective Effects Intensity of Cannabis Consumption: Factorial Structure Confirms Frequent Psychotic-like Experience in Young Adults

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: Reelin gene variants in autism

Autism is a complex neurodevelopmental disorder with severe cognitive and communication disabilities, that has a strong genetic predisposition. Reelin, a protein involved in neuronal migration during development, is encoded by a gene located on 7q22, within the candidate region on 7q showing increased allele sharing in previous genome scans. A case/control and family-based association study recently reported a positive association between a trinucleotide repeat polymorphism (GGC) located in the 5' untranslated region (UTR) of the reelin gene and autism. We performed a transmission disequilibrium test (TDT) analysis of the 5'UTR polymorphism in 167 families including 218 affected subjects (117 trios and 50 affected sib pairs) and found no evidence of linkage/association. Our results do not support previous findings and suggest that the reelin gene is unlikely to play a major role as a susceptibility factor in autism and/or genetic heterogeneity

Shame-proneness in patients with alcohol use disorder: gender differences

International audienc

Neurological soft signs in OCD patients with early age at onset, versus patients with schizophrenia and healthy subjects.

International audienceCompelling evidence suggests that both schizophrenia and obsessive compulsive disorder (OCD) are related to deviant neurodevelopment. Neurological soft signs (NSS) have been proposed to be a marker of abnormal brain development in schizophrenia. The purpose of this study is to examine whether NSS are also a marker in patients with OCD, in particular, in early-onset OCD. The authors included 162 subjects and compared patients with OCD, patients with schizophrenia (SCZ), and healthy control subjects. They were all examined for NSS (Krebs' Scale), extrapyramidal symptoms (Simpson-Angus Scale), and were rated on the Abnormal Involuntary Movements Scale (AIMS). The authors found no differences between NSS total scores and subscores in OCD versus controls, whereas total NSS, motor coordination, and motor integration were significantly lower in OCD than in SCZ. OCD patients with early-onset (before age 13) did not differ from those with later-onset OCD. These results support the idea that NSS, as determined by current scales, is relatively specific to schizophrenia, although they do not preclude the existence of a neurological dysfunction in OCD. Further studies are required to determine the type of neurological signs that could be useful trait-markers in the phenotypic characterization of subtype OCD

Bipolar disorders and quality of life: the impact of attention deficit/hyperactivity disorder and substance abuse in euthymic patients

Patients with bipolar disorders (BPD) display high rates of comorbidities, especially substance abuse (20-40%) and attention deficit/hyperactivity disorder (ADHD) (6%-20%). However, there are virtually no data evaluating the role of current ADHD on the global functioning of patients with BPD. The recent literature suggests that impairments in quality of life are a key prognostic feature for predicting the long course of BPD. The aim of this study was to investigate the intrinsic impact of adult ADHD and substance abuse in patients with BPD on levels of social adaptation, functioning and vitality. Seventy-three outpatients with BPD I or II, all euthymic and being treated with mood stabilizers, were evaluated using the following measures: 1) the Diagnostic Interview of Genetics Study for DSM-IV criteria; 2) the ADHD Self-Report Scale (ASRS) (screening of adult ADHD); 3) measures of quality of life: social adaptation (Social Adjustment Scale Self-Report (SAS-SR)), well-being (Short Form 36 (SF-36) Health Survey), and the Brief Psychiatric Rating Scale. In this clinical sample, 30% met the ADHD criteria and 22% were substance abusers. The results showed that the presence of ADHD in BPD patients significantly predicted a low social functioning and adaptation by comparison with BPD patients without ADHD. By contrast, we failed to detect a significant impact of substance abuse on those functional outcomes. This is the first step towards improved screening for comorbidities and an understanding of their crucial role in the prognosis of the disorder, as well as in defining new multilevel therapeutic strategies