Psychometric properties and normative data of the Latvian and Russian language versions of the strengths and difficulties questionnaire (SDQ) in the Latvian general adolescent population

Objectives: Mental health screening instruments are essential in population health research and clinical practice. The strengths and difficulties questionnaire (SDQ) self-report version has been widely used across the globe to screen for mental health problems in adolescent populations. This study aimed to explore the psychometric properties of the Latvian and Russian language versions of the SDQ in a representative sample of a general population of Latvian adolescents and establish the population-based normative scores. Materials and methods: This analysis was based on data from the international Health Behaviour in School-aged Children study year 2017/2018 Latvian database. The sample comprised 2683 Latvian and 1321 Russian-speaking 11-, 13-, and 15-year-old adolescents. Results: Significant language-based variance was observed in the mean scores of the externalising subscales of the SDQ, with Latvian-speaking adolescents reporting higher levels of conduct problems and hyperactivity. The reliability was satisfactory (ordinal alpha >0.7) only for the prosocial behaviour, emotional, internalising problems, and total difficulties subscales, while conduct, hyperactivity, peer, and externalising problems scales demonstrated lower internal consistency (ordinal alpha 0.5-0.7). Confirmatory factor analysis (CFA) did not support the hypothesised narrow-band five-factor or broad-band three-factor structure of the SDQ. The normative banding scores were calculated for both language variants. Conclusions: This study suggests that the self-report SDQ must be used cautiously in Latvian adolescents because some SDQ subscales lack reliability. When used in population research, the internalising subscales seem more reliable than the externalising ones. More research is needed regarding the reliability of the SDQ in clinical adolescent populations.