A prevalence study of Autism Spectrum Disorder in the Russian Federation

Autism Spectrum Disorder (ASD) is a neurodevelopmental condition marked by heterogeneity in presentation. In recent decades, ASD prevalence has risen globally, yet data from non-Western and middle-income countries, including Russia, remain scarce. Official statistics report a prevalence of 0.41 per 1000 (0.041%), far below global estimates of 32.2 per 1000 (3.2%), indicating underdiagnosis. This study provides the first population-based estimate of ASD prevalence among Russian elementary school children and examines barriers to diagnosis and treatment. The study followed a two-phase epidemiological approach. ASD identification used standardized instruments (SCQ, ADOS-2, ADI-R). The target population included all students in grades 1-3 (n = 34 847), stratified into mainstream, special education, and resource classes. ASD prevalence was estimated using Bayesian regression correcting for screening misclassification. The estimated ASD prevalence was 22.2 per 1000 children (95% CIs: 18.6-36.0), substantially exceeding what is reported based on the RF administrative data. The diagnostic phase had a 25.6% participation rate. ASD was more frequently identified in students from special education and resource classes than in general education settings. A Bayesian sensitivity analysis confirmed the robustness of prevalence estimates across plausible values for sensitivity and specificity. These findings suggest that ASD prevalence in Russia is considerably underestimated via administrative data. Systemic barriers--including limited access to diagnostic services and stigma surrounding psychiatric labels--may hinder ASD identification. Addressing these challenges is essential for improving early detection and service provision in Russia and similar contexts.