Development and Initial Validation of the Multidimensional Loneliness Questionnaire (MLQ): Study 1

This preregistration concerns Study 1 of the development of the Multidimensional Loneliness Questionnaire (MLQ), a new measure designed to assess multiple facets of loneliness across social, emotional, existential, intellectual, cultural, and situational domains. The primary aim of this study is to evaluate the psychometric structure of a preregistered item pool and to examine alternative structural representations of loneliness. Given ongoing theoretical debates regarding the dimensionality of loneliness, several candidate models will be explored, including correlated multidimensional models, hierarchical models including a general loneliness factor, and alternative parsimonious solutions where empirically justified. This preregistration fixes the dimension content and general analytical framework prior to data collection while allowing theory-informed flexibility regarding model comparison and dimensional/item refinement. Decisions regarding potential merging or reduction of dimensions will rely on model fit, parameter stability, conceptual interpretability, and external validity considerations.