Early Behavioural Markers of Autism Spectrum Disorder: A Narrative Review

Abstract

Background: Autism Spectrum Disorder (ASD) is a complex neurodevelopmental condition characterized by deficits in social communication and restricted, repetitive behaviours. Early identification of behavioural markers is critical for timely intervention and improved developmental outcomes.

Methods: A narrative review was conducted using electronic databases, including PubMed/MEDLINE, CINAHL, PsycINFO, and Google Scholar, covering publications from 2010 to 2024. Studies focusing on behavioural markers of ASD in children aged 0–36 months were included. A total of 17 peer-reviewed articles, encompassing prospective, retrospective, observational, screening-based, and review designs, were analyzed. Data were extracted on study characteristics, tools used, and key findings, and synthesized thematically.

Results: Early behavioural markers of ASD clustered into five domains: impaired social orienting and joint attention, atypical language and communication development, restricted and repetitive behaviours, sensory processing abnormalities, and reduced social smiling and affective responsiveness. These markers were identifiable as early as 6–12 months, particularly among high- risk infants. Screening and observational tools such as M-CHAT-R/F, AOSI, CSBS, and SACS demonstrated utility in early detection across clinical and community settings.

Conclusion: Early behavioural markers of ASD can be reliably identified prior to the conventional diagnostic age of 24–36 months. Nurses and primary healthcare providers play a critical role in developmental surveillance, caregiver education, and early referral. Integration of standardized screening tools into routine child health services is essential to enhance early detection and intervention outcomes.