Background: Given the high rates of suicide in the adolescent population and the reluctance of this population to seek help, developing proactive and effective strategies to timely detect individuals at high risk for suicide in non clinical contexts is a worldwide recognized need. A series of brief self-report questionnaires have been developed for this purpose, however there are few studies providing evidence on their capability to accurately classify suicidal risk levels in specific populations. One of the instruments frequently used to evaluate suicide risk is the Columbia-Suicide Severity Rating Scales (C-SSRS). The goal of this study is to provide psychometric evidence about the accuracy of the Suicidal Ideation subscale (SI) of the C-SSRS to classify suicidal risk levels in a sample of Chilean adolescents using Item Response Theory (IRT). Methods and materials: Through the two parameter logistic model (2-PLM), we analyzed the capability of a self report questionnaire addressing suicidal ideation (SI) to differentiate and classify participants according to their SI severity levels. We tested two main parameters: difficulty (localization) and discriminating power of 6 items extracted and adapted from the Columbia-Suicide Severity Rating Scales (C-SSRS). We administered this questionnaire to a general sample of 1645 adolescents aged 13 to 18. Results: Our results show that the items differentiate symptoms addressing suicidal thoughts according to their severity, providing an accurate classification of the SI risk level. Conclusions: These findings support the usage of the C-SSRS in Chilean adolescents. Further research is needed to test its predictive value in different populations. (C) 2018 Elsevier Inc. All rights reserved.

We tested first-order factor and bifactor models of attention-deficit/hyperactivity disorder (ADHD) using confirmatory factor analysis (CFA) and exploratory structural equation modeling (ESEM) to adequately summarize the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, (DSM-IV-TR) symptoms observed in a Spanish sample of preschoolers and kindergarteners. Six ESEM and CFA models were estimated based on teacher evaluations of the behavior of 638 children 4 to 6 years of age. An ESEM bifactor model with a central dimension plus 3 specific factors (inattention, hyperactivity, and impulsivity) showed the best fit and interpretability. Strict invariance between the sexes was observed. The bifactor model provided a solution to previously encountered inconsistencies in the factorial models of ADHD in young children. However, the low reliability of the specific factors casts doubt on the utility of the subscales for ADHD measurement. More research is necessary to clarify the nature of G and S factors of ADHD.