Suicide Attempts in Major Depressed Patients with Personality Disorder

Suicide attempters who met criteria for borderline personality disorder (BPD) comorbid with major depressive disorder (MDD) were compared to both suicide attempters suffering from MDD alone and to attempters with comorbid MDD and other personality disorders (PD). Participants were 239 (158 patients with comorbid PD and 81 patients with MDD without comorbidity) inpatients consecutively admitted after a suicide attempt made in the last 24 hours. Suicide attempters with comorbid MDD and BPD had more frequent previous suicide attempts and were more likely to have a history of aggressive behaviors and alcohol and drug use disorders compared with patients suffering from MDD without Axis II comorbidity.     

Finite Mixtures of Hidden Markov Models for Longitudinal Responses Subject to Drop out

Abstract

Drop out is a typical issue in longitudinal studies. When the missingness is non-ignorable, inference based on the observed data only may be biased. This paper is motivated by the Leiden 85+ study, a longitudinal study conducted to analyze the dynamics of cognitive functioning in the elderly. We account for dependence between longitudinal responses from the same subject using time-varying random effects associated with a heterogeneous hidden Markov chain. As several participants in the study drop out prematurely, we introduce a further random effect model to describe the missing data mechanism. The potential dependence between the random effects in the two equations (and, therefore, between the two processes) is introduced through a joint distribution specified via a latent structure approach. The application of the proposal to data from the Leiden 85+ study shows its effectiveness in modeling heterogeneous longitudinal patterns, possibly influenced by the missing data process. Results from a sensitivity analysis show the robustness of the estimates with respect to misspecification of the missing data mechanism. A simulation study provides evidence for the reliability of the inferential conclusions drawn from the analysis of the Leiden 85+ data.     

Penguins perceive variations of source- and filter-related vocal parameters of species-specific vocalisations

Animal Cognition - Animal vocalisations encode a wide range of biological information about the age, sex, body size, and social status of the emitter. Moreover, vocalisations play a significant...