Introdução: O Transtorno Obsessivo-Compulsivo (TOC) é reconhecido como um transtorno heterogêneo. Esta heterogeneidade dificulta a interpretação dos resultados dos estudos. A descrição de grupos de pacientes mais homogêneos pode facilitar a identificação desta busca, já que pode identificar fenótipos que sejam hereditários e válidos do ponto de vista genético. A abordagem categorial e dimensional são estratégias reconhecidas para a identificação de subgrupos mais homogêneos de pacientes. Dentro da abordagem categorial, o subgrupo de pacientes com início precoce dos sintomas obsessivo-compulsivo (SOC), e o subgrupo de TOC associado a transtorno de tiques apresentam características clínicas semelhantes, com evidências de sobreposição destas características entre os dois grupos. Os objetivos deste estudo foram: investigar características demográficas e clínicas dos pacientes com TOC de início precoce (GP) e TOC de início tardio (GT); e pesquisar características demográficas e clínicas dos pacientes com TOC de início precoce (GP) com tiques e pacientes com TOC de início precoce (GP) sem tiques. Metodologia: Trezentos e trinta pacientes com diagnóstico de TOC de acordo com o DSM-IV foram avaliados diretamente com os seguintes instrumentos: Entrevista Clínica Estruturada para o DSM-IV - Transtornos do Eixo I; Escala Yale-Brown de Sintomas Obsessivo-Compulsivos - Y-BOCS; Escala Dimensional para Avaliação de Presença e Gravidade de Sintomas Obsessivo-Compulsivos DY-BOCS; Escala de Avaliação Global de Tiques desenvolvida pelo Yale Child Study Center - YGTSS. Foi considerado TOC de início precoce se os sintomas dos pacientes tiveram início até os 10 anos de idade (160 pacientes). Os pacientes com início de sintomas entre 11 e 17 anos (95 pacientes) foram denominados grupo intermediário, enquanto aqueles após os 17 anos foram chamados grupo de início tardio (75 pacientes). Resultados: os pacientes do GP se diferenciaram dos pacientes do GT por apresentar maior freqüência do sexo masculino; maior freqüência de história familiar de SOC em familiares de primeiro grau; maiores escores da escala Y-BOCS para compulsões e Y-BOCS total; maior chance de ter obsessões de contaminação; maior chance de ter compulsões de repetição, colecionismo, diversas e compulsões do tipo tic-like; menor chance de ter compulsões de contagem; maior chance de apresentar sintomas da dimensão de \"colecionismo\"; maior gravidade nas dimensões de \"agressão/violência\", \"diversas\" e escore global da escala DY-BOCS; maior número médio de comorbidades; maior probabilidade de ocorrência de transtorno de ansiedade de separação, fobia social, transtorno dismórfico corporal e transtorno de tiques; menor chance de apresentar transtorno de estress pós-traumático; e maior chance de ter redução de 35% dos sintomas na escala Y-BOCS. O GP com tiques se diferenciou do GP sem tiques por apresentar maior prevalência de fenômenos sensoriais; menor chance e menor gravidade de ter a dimensão de \"contaminação/limpeza\" e menor gravidade no escore global da escala DY-BOCS; menor chance de apresentar transtorno de humor, transtorno unipolar, transtornos ansiosos, fobia social e skin picking, e maior a chance de apresentar diminuição de 35% dos sintomas na escala Y-BOCS. Os resultados sugeriram que as diferenças encontradas entre os grupos precoce, intermediário e tardio foram devidas à própria idade de início, e outras diferenças foram devidas à presença de tiques. / Introduction: Obsessive-compulsive disorder (OCD) is recognized as a heterogeneous condition. This heterogeneity obscures the interpretation of the results of the studies. The description of more homogeneous groups of patients can facilitate the identification of this search, since it can identify phenotypes that are hereditary and valid to the genetic point of view. Categorical and dimensional approaches are recognized strategies for the identification of more homogeneous subgroups of patients. Regarding the categorical approach, the subgroup of patients with early age at onset of the obsessive-compulsive symptoms (OCS), and the tic-related-OCD subgroup present similar clinical characteristics, with evidences of an overlap of these characteristics between the two groups. The aims of this study were: to investigate clinical and demographic characteristics of the early age at onset subgroup (EO), compared to the late onset subgroup (LO); and to investigate demographic and clinical characteristics of early age at onset OCD patients, with and without comorbid tic disorders. Methodology: Three hundred and thirty patients with the diagnosis of OCD according to the DSM-IV were directly assessed with the following instruments: Structured Clinical Interview for DSM-IV Axis I Disorders-patient edition - SCID-I/P; Yale-Brown Obsessive-Compulsive Scale - Y-BOCS; Dimensional Yale-Brown Obsessive-Compulsive Scale - DY-BOCS and Yale Global Tics Severity Scale - YGTSS. We considered early age at onset when OCS began before the age of 10 (160 patients). Patients with age at onset between 11 and 17 years old were termed intermediate group (95 patients), whereas those with age at onset after 17 years old were designated as late onset OCD (75 patients). Results: EO patients differed from LO patients in terms of presenting higher frequency of the male gender; higher frequency of a family history of OCS; higher Y-BOCS for compulsions and total Y-BOCS scores; higher chance of presenting contamination obsessions, repeating, hoarding, miscellaneous and tic-like compulsions; lower chance of having counting compulsions; higher probability of presenting symptoms of \"hoarding\" dimension; higher severity in \"aggression/violence\" and \"miscellaneous\" dimensions and global DY-BOCS scale score; higher mean number of comorbidities; higher probability of presenting separation anxiety disorder, social phobia, body dysmorphic disorder and tic disorders; lower chance of presenting posttraumatic stress disorder; and a higher chance of having a 35% reduction on the Y-BOCS scale. The EO subgroup with tic disorders differed from the EO without tics for presenting higher chance of having sensory phenomena, somatic obsessions; lower chance and lower score in the DY-BOCS scale; lower chance of presenting mood disorder, depressive disorder, anxiety disorders, social phobia and skin picking; higher chance of having a 35% reduction on the Y-BOCS scale. Results suggested that the differences found among early, intermediated and late onset groups with early onset were secondary to the own age at onset, and other differences were secondary to the presence of tics.

Prevalence findings for 1995 of illicit drug use as well as DSM-IV abuse and dependence are reported from a representative population sample of 3,021 respondents from Munich, Germany, aged 14–24 years. Results are based on personal interviews using the M-Composite International Diagnostic Interview (M-CIDI) with its DSM-IV diagnostic algorithms. Findings indicate that more than 30% of the adolescents and young adults are or have been using one or more illicit drugs at least once in their life. Men were slightly more likely to ever use drugs and used them more frequently than women. Cannabinoids were by far the most frequently used type of drug, followed by various stimulating drugs and hallucinogens. There is also considerable polysubstance use among 14- to 24-year-olds. Criteria for DSM-IV abuse without dependence were met by 4.1% of all men and 1.8% of all women, a dependence syndrome of any type of illicit drug was diagnosed in 2.5% of the men and 1.6% of the women. Cumulative age of onset incidence analyses suggest that substance use starts early, in about one-third before the age of 16 years and continues to rise for most drugs throughout adolescence and young adulthood. Overall these findings suggest that substance use and substance disorders are more prevalent than suggested in most previous German studies.

No description available.

Background: When assessing the association between a factor X and a subsequent outcome Y in observational studies, the question that arises is what are the variables to adjust for to reduce bias due to confounding for causal inference on the effect of X on Y. Disregarding such factors is often a source of overestimation because these variables may affect both X and Y. On the other hand, adjustment for such variables can also be a source of underestimation because such variables may be the causal consequence of X and part of the mechanism that leads from X to Y. Methods: In this paper, we present a simple method to compute control variables in the presence of age at onset data on both X and a set of other variables. Using these age at onset data, control variables are computed that adjust only for conditions that occur prior to X. This strategy can be used in prospective as well as in survival analysis. Our method is motivated by an argument based on the counterfactual model of a causal effect. Results: The procedure is exemplified by examining of the relation between panic attack and the subsequent incidence of MDD. Conclusions: The results reveal that the adjustment for all other variables, irrespective of their temporal relation to X, can yield a false negative result (despite unconsidered confounders and other sources of bias).

Background: When assessing the association between a factor X and a subsequent outcome Y in observational studies, the question that arises is what are the variables to adjust for to reduce bias due to confounding for causal inference on the effect of X on Y. Disregarding such factors is often a source of overestimation because these variables may affect both X and Y. On the other hand, adjustment for such variables can also be a source of underestimation because such variables may be the causal consequence of X and part of the mechanism that leads from X to Y. Methods: In this paper, we present a simple method to compute control variables in the presence of age at onset data on both X and a set of other variables. Using these age at onset data, control variables are computed that adjust only for conditions that occur prior to X. This strategy can be used in prospective as well as in survival analysis. Our method is motivated by an argument based on the counterfactual model of a causal effect. Results: The procedure is exemplified by examining of the relation between panic attack and the subsequent incidence of MDD. Conclusions: The results reveal that the adjustment for all other variables, irrespective of their temporal relation to X, can yield a false negative result (despite unconsidered confounders and other sources of bias).

Les fonctions cognitives reposent sur la communication dynamique de régions cérébrales interconnectées. Dans la maladie d’Alzheimer (MA), les travaux antérieurs suggèrent que le processus neuropathologique cible de façon précoce un ou plusieurs systèmes anatomo-fonctionnels spécifiques. La dysfonction du réseau par défaut a été objectivée de façon consistante. Cependant, ses relations avec les symptômes cliniques et avec l’atteinte des régions du lobe temporal interne qui lui sont fonctionnellement connectées restent à clarifier. L’IRM fonctionnelle de repos est une technique pertinente pour caractériser in vivo chez l’Homme la connectivité cérébrale.Par une approche des systèmes neuraux, ce travail de thèse a pour objectif de caractériser la réorganisation fonctionnelle neuronale dans la MA, ses corrélats cliniques, ainsi que l’influence de l’âge de début des symptômes. Par le recueil et l’analyse des données neuropsychologiques, en IRMf de repos et en IRM structurale, acquises chez des sujets avec des troubles de la mémoire et avec une forme mnésique légère de MA, notre travail apporte des éclairages : i) sur l’implication du réseau temporal antérieur dans la mémoire déclarative décontextualisée et ses modifications dans le cours de la MA ; ii) sur les similitudes et spécificités des systèmes anatomo-fonctionnels ciblés dans les deux formes cliniques distinctes - à début précoce et tardif - de la MA ; iii) sur la réorganisation de l’organisation topologique cérébrale dans son ensemble de ces deux formes de la maladie. / Cognitive functions rely on the dynamic interplay of connected brain regions. Previous studies suggest that in Alzheimer disease (AD), early pathological changes target one or several specific anatomo-functional networks. Dysfunction of the default mode network is a consistent finding. However, its relationship with clinical symptoms and interconnected medial temporal regions remains to be clarified. Resting state functional MRI (fMRI) is an emerging method aimed at characterizing in vivo brain connectivity in the Human.Using a neural system approach, the aim of this thesis was to characterize neuronal functional reorganization in AD, its clinical correlates, and to determine the influence of age at onset. Neuropsychological data, structural and fMRI were obtained in subjects with early memory impairment and mild “amnestic” AD. This work provides new insights into : i) the functional role of the anterior temporal network in context-free declarative memory and its changes throughout the course of AD; ii) the common and specific features in targeted anatomo-functional networks between early and late onset AD ; iii) the reorganization of whole brain topological properties in the two forms of the disease.

L'asma és una malaltia d'etiologia complexa, formada per factors genètics i ambientals, on la interrelació de ambdós factors mitjançant interaccions gen-ambient juga un paper clau. L'objectiu d'aquesta tesi ha sigut aprofundir en el coneixement del paper dels polimorfismes genètics, i la seva interacció amb factors ambientals, en la ocurrència d'asma, atòpia i hiperreactivitat bronquial. Aquest objectiu ha estat desenvolupat a través de la replicació de variants genètiques prèviament identificades, l'avaluació d'interaccions gen-ambient i la identificació de nous gens de susceptibilitat mitjançant un disseny basat en el genotipatge de variants genètiques all llarg del genoma en pools d'ADN. La tesi ha estat majoritàriament duta a terme dins l'estudi European Community Respiratory Health Survey (ECRHS) que està comprès per 5.000 individus seguits durant 9 anys, pels quals es disposa d'un qüestionari complet sobre símptomes respiratoris, avaluacions clíniques, informació sobre exposicions ambientals i mostres de ADN. Aquesta tesi a replicat l'associació del polimorfismes dels gens TNFA i NPSR1 amb asma. A més s'han establert les interaccions entre TNFA i obesitat, NQO1 i contaminació atmosfèrica, i NPSR1 i edat d'inici d'asma. L'anàlisi de pools d' ADN ha permès associar la regió on es situa el gen SGK493 amb atòpia. Aquesta tesi contribueix al coneixement de l'etiologia d'asma amb la identificació i replicació d'associacions genètiques i interaccions gen-ambient. / Asthma is a disease with a complex etiology, involving multiple genetic and environmental factors, and with an important role of the interplay of these factors through gene-environment interactions. In this thesis I aimed to advance our knowledge on the importance of genetic polymorphisms and their interaction with environmental data for the occurrence of asthma and related phenotypes (atopy and bronchial hyperreactivity). This objective was developed through the replication of genetic associations previously reported, the assessment of gene-environment interactions and the identification of new susceptibility genes using genome-wide analysis based on a pooling DNA strategy. The thesis was, mostly, performed within the European Community Respiratory Health Survey (ECRHS). This cohort has information and DNA samples from approximately 5,000 adult subjects followed-up for 9 years, with extensive questionnaires on respiratory symptoms, clinical evaluations and information on environmental exposures. This thesis replicates previous effects on asthma of polymorphisms in TNFA and NPSR1 genes. In addition, interactions have been established between TNFA and obesity, NQO1 and air-pollution, and NPSR1 and age at onset of asthma. The approach based on genome-wide analysis of DNA pools identified the SGK493 region being associated with atopy. This thesis contributes to the understanding of the etiology of asthma through the identification and replication of genetic associations and gene-environment interactions.