Individual prediction of cognitive decline in mild cognitive impairment using support vector machine-based analysis of diffusion tensor imaging data.

Although cross-sectional diffusion tensor imaging (DTI) studies revealed significant white matter changes in mild cognitive impairment (MCI), the utility of this technique in predicting further cognitive decline is debated. Thirty-five healthy controls (HC) and 67 MCI subjects with DTI baseline data were neuropsychologically assessed at one year. Among them, there were 40 stable (sMCI; 9 single domain amnestic, 7 single domain frontal, 24 multiple domain) and 27 were progressive (pMCI; 7 single domain amnestic, 4 single domain frontal, 16 multiple domain). Fractional anisotropy (FA) and longitudinal, radial, and mean diffusivity were measured using Tract-Based Spatial Statistics. Statistics included group comparisons and individual classification of MCI cases using support vector machines (SVM). FA was significantly higher in HC compared to MCI in a distributed network including the ventral part of the corpus callosum, right temporal and frontal pathways. There were no significant group-level differences between sMCI versus pMCI or between MCI subtypes after correction for multiple comparisons. However, SVM analysis allowed for an individual classification with accuracies up to 91.4% (HC versus MCI) and 98.4% (sMCI versus pMCI). When considering the MCI subgroups separately, the minimum SVM classification accuracy for stable versus progressive cognitive decline was 97.5% in the multiple domain MCI group. SVM analysis of DTI data provided highly accurate individual classification of stable versus progressive MCI regardless of MCI subtype, indicating that this method may become an easily applicable tool for early individual detection of MCI subjects evolving to dementia.

Las relaciones actitud-conducta y'otras variables' a partir de la teoría de Fishbein y Ajzena y del modelo LISREL: Estudio empírico

A través de la investigación presentada en este articulo se ha pretendido operacionalizar la parte predictiva de la Teoria de Acción Razonada, propuesta por Fishbein y Ajzen. Para ello, se ha utilizado la reciente metodologia de 10s modelos de ecuaciones estructurales lineales con variables latentes desarrollados por Joreskog y Sorbom, entre otros. Como dominio se ha delimitado el consumo de tabaco en distintas situaciones sociales. Después de estimar y valorar el modelo predictivo especificado desde la Teoria de Fishbein y Ajzen, se estimo y valoro el modelo generalizado propuesto por Bentler y Speckart y se asumió como mas coherente este modelo generalizado. En el trabajo también se plantean una serie de observaciones para optimizar, sobre todo, la parte metodológica de recogida de datos asociados a estos modelos y se presenta una propuesta para operacionalizar todo el sistema teórico de predicción y explicación de las conductas desde la Teoria de Fishbein y Ajzen.

A productivity map of cognitive pretest methos for improving survey questions

Interest in cognitive pretest methods for evaluating survey questionnaires has been increasing for the last three decades. However, analysing the features of the scientific output in the field can be difficult due to its prevalence in public and private institutes whose main mission is not scientific research. The aim of this research is to characterize the current state of scientific output in the field by means of two bibliometric studies for the period from 1980 to 2007. Study 1 analysed documents obtained from the more commonly used bibliographic databases. Study 2 supplemented the body of documents from Study 1 with documents from non-indexed journals, conference papers, etc. Results show a constant growth in the number of publications. The wide dispersion of publication sources, together with the highlighted role of the public and private institutions as centres of production, can also be identified as relevant characteristics of the scientific output in this field.

Retaining principal components for discrete variables

The present study discusses retention criteria for principal components analysis (PCA) applied to Likert scale items typical in psychological questionnaires. The main aim is to recommend applied researchers to restrain from relying only on the eigenvalue-than-one criterion; alternative procedures are suggested for adjusting for sampling error. An additional objective is to add evidence on the consequences of applying this rule when PCA is used with discrete variables. The experimental conditions were studied by means of Monte Carlo sampling including several sample sizes, different number of variables and answer alternatives, and four non-normal distributions. The results suggest that even when all the items and thus the underlying dimensions are independent, eigenvalues greater than one are frequent and they can explain up to 80% of the variance in data, meeting the empirical criterion. The consequences of using Kaiser"s rule are illustrated with a clinical psychology example. The size of the eigenvalues resulted to be a function of the sample size and the number of variables, which is also the case for parallel analysis as previous research shows. To enhance the application of alternative criteria, an R package was developed for deciding the number of principal components to retain by means of confidence intervals constructed about the eigenvalues corresponding to lack of relationship between discrete variables.

Assessing the associations between mental disorders, cardiovascular risk factors, and cardiovascular disease : the CoLaus/PsyCoLaus study

Background: Cardio-vascular diseases (CVD), their well established risk factors (CVRF) and mental disorders are common and co-occur more frequently than would be expected by chance. However, the pathogenic mechanisms and course determinants of both CVD and mental disorders have only been partially identified.Methods/Design: Comprehensive follow-up of CVRF and CVD with a psychiatric exam in all subjects who participated in the baseline cross-sectional CoLaus study (2003-2006) (n=6'738) which also included a comprehensive genetic assessment. The somatic investigation will include a shortened questionnaire on CVRF, CV events and new CVD since baseline and measurements of the same clinical and biological variables as at baseline. In addition, pro-inflammatory markers, persistent pain and sleep patterns and disorders will be assessed. In the case of a new CV event, detailed information will be abstracted from medical records. Similarly, data on the cause of death will be collected from the Swiss National Death Registry. The comprehensive psychiatric investigation of the CoLaus/PsyCoLaus study will use contemporary epidemiological methods including semi-structured diagnostic interviews, experienced clinical interviewers, standardized diagnostic criteria including threshold according to DSM-IV and sub-threshold syndromes and supplementary information on risk and protective factors for disorders. In addition, screening for objective cognitive impairment will be performed in participants older than 65 years.Discussion: The combined CoLaus/PsyCoLaus sample provides a unique opportunity to obtain prospective data on the interplay between CVRF/CVD and mental disorders, overcoming limitations of previous research by bringing together a comprehensive investigation of both CVRF and mental disorders as well as a large number of biological variables and a genome-wide genetic assessment in participants recruited from the general population.

School burnout in adolescents : Differences in background variables and exploration of school-related stress at the end of compulsory schooling

The aim of this study is to contribute to a better understanding of the risk factors associated with school burnout, which has recently been described as a syndrome of emotional exhaustion due to school demands, cynical and detached attitude towards school and feelings of inadequacy as a student (Salmela-Aro, Kiuru, Pietikainen & Jokela, 2008a). The research focuses on students in the last years of compulsory schooling, period in which burnout has not received much attention yet. A total of 342 adolescents (Mean age = 14.84) were asked to complete questionnaires about school burnout, school-related stress and background variables. The results showed differences in school burnout by gender, grade level and school track, with girls, last grade of compulsory school and high-track classes, showing the highest scores. No difference was observed with respect to grade retention. Several types of school stress were identified, with stress type Success related to pressures to succeed and concerns about the academic future being the highest. Finally, stress and burnout were strongly and positively correlated, and the type of stress Success was the best predictor of overall Burnout, Exhaustion and Inadequacy dimension scores. The results are discussed in relation to their theoretical relevance and implications for the prevention of school burnout in adolescents.

Self construction, cognitive conflicts and polarization in bulimia nervosa

This study explores the cognitive structures, understood as construct systems, of patients suffering from bulimia nervosa (BN). Previous studies investigated the construct systems of disordered eaters suggesting that they had a higher distance between their construction of the self and the «ideal self», and also more rigidity. In addition to these aspects, this study explored the presence of implicative dilemmas (ID). Thirty two women who met criteria for BN and were treated in a specialized center were compared to a non clinical group composed by 32 women matched by age. All participants were assessed using Repertory Grid Technique (RGT). In BN patients it was more common (71.9%) to find IDs than in controls (18.8%). They also showed higher polarization and higher self-ideal discrepancies (even more for those with a long history of BN). The measures provided by the RGT can be useful for the assessment of self-construction and cognitive conflicts in BN patients and to appreciate their role in this disorder. In addition, this technique could be helpful for clinicians to explore the patient"s constructs system, and specially to identify IDs that could be maintaining the symptoms or hindering change in order to focus on them to facilitate improvement.

Family burden related to clinical and functional variables of people with intellectual disability with and without a mental disorder

Few studies have been found that to assess the factors that explain higher levels of familyburden in adults with intellectualdisability (ID) and intellectualdisability and mental disorders (ID-MD). The aims of this study were to assess familyburden in people with ID and ID-MD and to determine which sociodemographic, clinical and functionaldisabilityvariables account for familyburden. The sample is composed of pairs of 203 participants with disability and their caregivers, of which 33.5% are caregivers of people with ID and 66.5% of ID-MD. Assessments were performed using scales of clinical and functionaldisability as the following instruments: Weschler Adult Intelligence Scale-III (WAIS-III), Inventory for Client and Agency Planning (ICAP), Psychiatric Assessment Schedule for Adults with Development Disability (PAS-ADD checklist), Disability Assessment Schedule of the World Health Organization (WHO-DAS-II) and familyburden (Subjective and Objective FamilyBurden Inventory - SOFBI/ECFOS-II). People with ID-MD presented higher levels of functionaldisability than those with ID only. Higher levels of familyburden were related to higher functionaldisability in all the areas (p < 0.006-0.001), lower intelligence quotient (p < 0.001), diagnosis of ID-MD (p < 0.001) and presence of organic, affective, psychotic and behavioral disorders (p < 0.001). Stepwise multiple regression showed that behavioral problems, affective and psychotic disorder, disability in participation in society, disability in personal care and presence of ID-MD explained more than 61% of the variance in familyburden. An integrated approach using effective multidimensional interventions is essential for both people with ID and ID-MD and their caregivers in order to reduce familyburden.

Cognitive behavioural therapy for obesity and binge eating associated to antipsychotic drugs

Background and Aims: Overweight, obesity and binge eating disorder are commonly reported in persons with severe mental disorders. Particularly, antipsychotic drugs (AP) induce weight gain in up to half of the patients. The aim of the present study is to confirm a previous study results on a larger sample of patients, to assess the impact of the interventions on other relevant dimensions of eating and weight related cognitions as well as to assess potential clinical indicators of outcomes such as AP drug, concomitant treatment with lithium or carbamazepine, psychiatric diagnostic, binge eating and severity of cognitive distortions. Method: A controlled study (12-week CBT vs. B N E) was carried out on 99 patients treated with an AP and who have gained weight following this treatment. Binge eating symptomatology, eating and weight-related cognitions, as well as weight and body mass index were assessed before treatment, at 12 weeks and at 24 weeks. Results: The findings confirms usefulness and effectiveness of the proposed CBT program on the treatment of binge symptomatology, cognitive distortions and obesity in patients treated with AP. Reduction of binge symptoms and maladapted cognitions appeared early, whereas the effect on weight appeared later during the follow up observation. No differences on outcomes were found across pharmacotherapy characteristics, diagnostic categories, binge eating nor severity of cognitive distortions. Conclusion: The proposed CBT treatment is useful for patients suffering from weight gain associated with AP treatments indeed when a concomitant treatment with lithium or valproate was given.

The relationship between cognitive errors and interpersonal patterns in depressed women.

Individuals with depression process information in an overly negative or biased way (e.g., Henriques & Leitenberg, 2002) and demonstrate significant interpersonal dysfunction (e.g., Zlotnick, Kohn, Keitner, & Della Grotta, 2000). This study examined the relationship between cognitive errors (CEs) and interpersonal interactions in early psychotherapy sessions of 25 female patients with major depression. Transcripts were rated for CEs using the Cognitive Error Rating Scale (Drapeau, Perry, & Dunkley, 2008). Interpersonal patterns were assessed using the Structural Analysis of Social Behavior (Benjamin, 1974). Significant associations were found between CEs and markers of interpersonal functioning in selected contexts. The implications of these findings in bridging the gap between research and practice, enhancing treatment outcome, and improving therapist training are discussed. (PsycINFO Database Record (c) 2012 APA, all rights reserved).