Psychometric Validation and Cross-Cultural Invariance of the Arabic K-SADS-PL-C DSM-5: A Multi-Site Diagnostic Study

Background Accurate diagnosis of psychiatric disorders in children and adolescents is essential for effective clinical care, valid research, and targeted interventions. Given the high burden of mental disorders in the Middle East and North Africa (MENA) region and limited validated Arabic diagnostic interviews aligned with DSM-5, rigorous psychometric evaluation of the Arabic Kiddie Schedule for Affective Disorders and Schizophrenia—Present and Lifetime Version, Comprehensive DSM-5 (K-SADS-PL-C DSM-5) is needed. Methods We conducted a multi-site psychometric validation study with 200 participants aged 6–18 years (n = 100 from Saudi Arabia and n = 100 from Egypt"), recruited from clinical (70%) and community (30%) settings in Hail, Saudi Arabia, and Cairo, Egypt. The Arabic version was developed via forward–back translation and expert-panel cultural adaptation. Reliability was assessed using inter-rater (n = 40) and test–retest (n = 30; 7–14-day interval) analyses with Cohen’s κ and Gwet’s AC1 for low-prevalence diagnoses. Criterion validity was evaluated against blinded Consensus Clinical Diagnosis (CCD) by senior psychiatrists. Multi-group confirmatory factor analysis (MG-CFA) examined configural, metric, and scalar invariance across sites. Results Inter-rater κ ranged from 0.81 to 1.00 (AC1 ≥ 0.85), and test–retest κ ranged from 0.85 to 0.96 (AC1 ≥ 0.88) across selected DSM-5 diagnoses. Internal consistency was high (α = 0.92 internalising; α = 0.94 externalising). Against CCD, sensitivity ranged from 86.7% to 100% and specificity from 97.1% to 100% for selected disorders (AUC 0.93–1.00). MG-CFA supported scalar invariance (ΔCFI − 0.002; ΔRMSEA − 0.001), enabling cross-site comparisons. Prevalence estimates were comparable between countries (χ² p > 0.4 across selected disorders). Conclusions The Arabic K-SADS-PL-C DSM-5 demonstrates excellent reliability, strong criterion validity, and evidence of measurement invariance across Saudi and Egyptian samples, supporting its use for standardised assessment and multi-site research in Arabic-speaking youth.