Autism Spectrum Disorder and the importance of timely diagnosis

 Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterised by persistent deficits in social communication/interaction across contexts (Criteria A), and restricted, repetitive patterns of behaviours, interests, or activities (Criteria B). These symptoms typically present from early childhood and limit or impair everyday functioning (Criteria C and B). 

According to the recent DSM-5-TR (American Psychiatric Association, 2022) criteria, deficits in social communication/interaction are manifested as difficulties in social-emotional reciprocity (i.e., back-and-forth exchange in social interactions), non-verbal communicative behaviours, and challenges in developing, maintaining, and understanding relationships. The restricted and repetitive patterns in ASD are often manifested as repetitive motor movements (e.g., hand flapping, echolalia, etc.), insistence on sameness (e.g., extreme distress at small changes), highly fixated interests, and hyper- or hypo-reactivity to sensory input (e.g., distress at specific sounds) (American Psychiatric Association, 2022). 

Across countries, the prevalence of ASD has been continuously increasing, with the prevalence in the US having increased from 1-in-150 to 1-in-31 (Shaw et al., 2025), as well as in other countries including Australia, and Taiwan (Zeidan et al., 2022). Despite the rise in ASD diagnoses–due in part to increased awareness and improved access to screening– late-diagnosis of ASD still remains partially due to a reluctance to screen children for ASD. 

This hesitation is understandable, given the persistent stigma surrounding ASD, which can affect not only individuals with the condition but also their caregivers and families. However, it is important to consider the emotional, behavioural, and social difficulties that can be associated with the timing of an ASD diagnosis. 

For instance, research has shown that compared to those who receive a timely (i.e., early) diagnosis, late-diagnosed autistic children (i.e., those not identified until after starting primary education) may present with milder difficulties in early childhood, but later experience steeper increases in emotional, behavioural, and social challenges (Mandy et al., 2022), ultimately impacting their quality of life. In fact, a delayed diagnosis of children especially with mild symptoms of ASD often results in missed opportunities for early intervention to address these difficulties (Lupindo et al., 2023). 

As a result, the early signs of ASD can easily be overlooked or even minimised, affecting children’s overall developmental experiences. Timely screening and diagnosis not only support early interventions but also create opportunities for children with ASD and their caregivers to better understand the challenges they face and to build effective coping strategies. 

Seeking a diagnosis does not mean rushing to place a label or define a child’s future. Rather, it offers a path toward understanding them better. Early diagnosis can help make sense of challenges that might otherwise feel confusing or isolating, and it opens the door to support that can truly make a difference. For many families, it would be learning how best to support and connect with them. And in that journey, earlier understanding can often bring a little more clarity, and a lot more compassion for both the child and the families. 

American Psychiatric Association. (2022). Diagnostic and statistical manual of mental disorders (5th ed., text rev.). https://doi.org/10.1176/appi.books.9780890425787 

Shaw, K.A. et al. (2025). Prevalence and early identification of autism spectrum disorder among children aged 4 and 8 years — autism and developmental disabilities monitoring network, 16 sites, United States, 2022, MMWR. Surveillance Summaries, 74(2), 1–22. https://doi.org/10.15585/mmwr.ss7402a1 

Zeidan, J., Fombonne, E., Scorah, J., Ibrahim, A., Durkin, M. S., Saxena, S., Yusuf, A., Shih, A., & Elsabbagh, M. (2022). Global Prevalence of autism: a Systematic Review Update. Autism Research, 15(5), 778–790. https://doi.org/10.1002/aur.2696 

Mandy, W., Midouhas, E., Hosozawa, M., Cable, N., Sacker, A., & Flouri, E. (2022). Mental health and social difficulties of late‐diagnosed autistic children, across childhood and adolescence. Journal of Child Psychology and Psychiatry, 63(11). https://doi.org/10.1111/jcpp.13587 

Lupindo, B. M., Maw, A., & Shabalala, N. (2022). Late Diagnosis of autism: Exploring Experiences of Males Diagnosed with Autism in Adulthood. Current Psychology, 42(28). https://doi.org/10.1007/s12144-022-03514-z