Creation and Validation of the Madrid Loneliness Questionnaire in Spanish Population

Loneliness is a growing concern in contemporary societies, particularly in urban environments, where social dynamics are rapidly evolving. Existing measures may not fully capture the complexity of loneliness in the context of ongoing technological and social changes. This study introduces the Madrid Loneliness Questionnaire (MLQ), a new instrument designed to assess loneliness in adults within modern sociocultural contexts. A sample of 1,526 adults (77.1% women; 18-87 years) participated in the study. The sample was randomly divided for structural validation: one subsample underwent exploratory factor analysis (EFA, n = 623) and the other confirmatory factor analysis (CFA, n = 903). Measurement invariance across gender and age was examined using multigroup CFA. Convergent validity was assessed through correlations with self-esteem and perceived stress. Internal consistency was evaluated using Cronbach's alpha and McDonald's omega. EFA and CFA supported a three-factor structure with excellent fit indices (Comparative Fit Index = 0.998; Tucker-Lewis Index = 0.997; RMSEA = 0.019; SRMR = 0.05): Social Skills, Partner Relationships, and Emotional Isolation. Multigroup CFA confirmed scalar invariance across gender and age. Significant gender differences were found in Social Skills (higher in men) and Partner Relationships (higher in women). The oldest age group (>65 years) scored higher on Partner Relationships than younger groups. The MLQ and its subscales showed moderate to strong negative correlations with self-esteem (rho = -.36 to -.63) and positive correlations with perceived stress (rho = .25 to .49). The scale demonstrated excellent internal consistency (α = .93, ω = .92). The MLQ is a psychometrically sound instrument for assessing loneliness in adults, enabling tailored interventions by serving as a basis for public health policies.