Underdiagnosis of autism spectrum disorder: a narrative review of gender differences and systemic barriers

Purpose This paper examines the persistent underdiagnosis of autism spectrum disorder, particularly among women, adults and minority groups. This study aims to identify how gendered symptom expression, camouflaging behaviours, systemic barriers and cultural inequities affect diagnostic accuracy and timeliness. Design/methodology/approach A structured narrative review of 33 peer-reviewed empirical studies published between 2009 and 2024, with one historical paper from 1992 retained for context. Sources were retrieved from PubMed, Scopus and Web of Science. We used controlled vocabulary and free-text terms. Methodological quality was appraised with critical appraisal skills programme, Joanna Briggs Institute and A Measurement Tool to Assess Systematic Reviews, version 2. Reporting followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020. Findings were synthesised across four domains: gender differences in diagnostic timing, camouflaging and phenotypic variability, systemic barriers and cultural and linguistic factors. Findings Standard diagnostic frameworks (Diagnostic and statistical manual of mental disorders, Fifth Edition, International Classification of Diseases, 11th Revision) demonstrate limited sensitivity for atypical presentations, particularly among females and high-ability individuals. Delays are compounded by cultural and linguistic barriers, clinician knowledge gaps and fragmented services. Multimodal assessment and targeted clinician training are linked to better detection and greater equity. Research limitations/implications The included studies varied in methods and populations, which limits the generalisability of findings. Longitudinal and neurobiological evidence is scarce, especially in low- and middle-income countries. Future studies should validate culturally adapted screening tools and explore the neural basis of camouflaging. Practical implications Routine screening in primary care, clearer referral pathways, culturally adapted instruments and telehealth-enabled access may reduce diagnostic delays and disparities. Tailored clinician education may also improve early recognition and reduce misdiagnosis. Originality/value This review integrates gender, cultural and system-level perspectives on autism spectrum disorder underdiagnosis, offering actionable guidance for clinicians, educators and policymakers to support timely and equitable diagnosis.