A “both-and” approach to cross-cultural mental health assessment: Examining adolescent depression and anxiety symptoms using both local and western-derived instruments in Kenya

Cross-cultural mental health assessment faces methodological challenges when Western-derived instruments are applied in non-Western settings, potentially missing culturally salient expressions of distress. This study examines whether locally developed instruments complement Western tools in assessing adolescent mental health among Kenyan youth. We evaluated the Ndetei-Othieno-Kathuku (NOK) Scale alongside the PHQ-8 and GAD-7 in 2906 Kenyan adolescents (M age = 16.06, SD = 1.51; 52.9% female) across 40 secondary schools. Using exploratory and confirmatory factor analyses, receiver operating characteristic curves (ROC), multidimensional scaling, and network analysis, we examined psychometric properties, symptom overlap, screen-positive thresholds, and associations with sociodemographic factors. The NOK scales demonstrated poor-to-adequate internal consistency (NOK-Anxiety α = .78; NOK-Depression α = .61) with distinct factor structures from Western instruments. ROC-derived screening cutoffs (calibrated against PHQ-8 ≥ 10 and GAD-7 ≥ 10) were 3.5 for depression and 6.5 for anxiety (AUC = .72–.77). Screen-positive prevalence was higher using the NOK-derived thresholds (45.91% depression, 32.11% anxiety) than using PHQ-8 (27.28%) or GAD-7 (21.95%). Multidimensional scaling revealed clustering by instrument origin, while network analysis showed NOK items had higher centrality. Age, gender, perceived academic ability, family structure, and parental loss were associated with screen-positive status. Locally developed and Western-derived instruments provide complementary information about adolescent mental health. This “both-and” approach captures culturally specific distress while maintaining cross-cultural comparability, supporting more comprehensive assessment in diverse contexts.