Autism assessment is often organised around a single visit, while developmental changes in autistic children and adults may unfold gradually over time. Longitudinal research suggests that some of these changes can go unnoticed, while some apparent changes may reflect something other than development. Repeated assessments can offer insights that a single visit may miss.
Follow-up after the first assessment
Much of the focus in autism assessment tends to be on the initial appointment. Waiting lists are long, and services are under pressure to see more people more quickly, so follow-up can be harder to prioritise.
In her session, Autism Assessment Across the Lifespan, Catherine Lord drew on her longitudinal research with children referred for possible autism at age two and followed into adulthood. She suggested that follow-up assessments can often be more informative than the initial assessment. This is partly because an initial assessment captures a person at a particular point in their development, often at a time of uncertainty for the family. How that person will develop over time, and at what pace, is much harder to predict.
Scores that shifted slowly over years
In Lord’s longitudinal work, many children showed relatively stable autism severity scores throughout childhood (Gotham et al., 2012). Into adulthood, the picture became more varied. Lord described assessments carried out mostly in participants’ homes, by examiners who did not know earlier results. Among those diagnosed with autism at two, a group showed severity scores that fell gradually over many years, while a smaller group showed the opposite pattern, with scores increasing as they grew older (Elias & Lord, 2022). Lord had expected, if anything, a sharper change around adolescence; the gradual slope only became visible once the data were examined over time. A single assessment would not have revealed either trajectory.
Reports of change can mislead
Repeated assessment also raises the question of what counts as change. In one study, parents and carers reported improvements in their children’s behaviour despite no treatment being provided, while clinician ratings showed no significant change (Jones et al., 2017).
Parent reports remain central to autism assessment, offering details about a child’s development and everyday experiences. However, parents’ observations can also be influenced by their hopes and expectations, making these reports more difficult to use as the sole measure of change. One approach to addressing this challenge is the Brief Observation of Social Communication Change (BOSCC), which uses video-recorded play-based observations and a coding system designed to capture subtle changes in social communication that traditional diagnostic instruments may be less sensitive to (Grzadzinski et al., 2016).
Daily living skills over time
Beyond changes in assessment scores, adaptive skills offer another perspective on development. In the same cohort, many participants showed daily living skills below what their cognitive ability would suggest (Bal et al., 2015).
Some changes in daily life are small and hard to score. Lord also described one young man with significant intellectual disability who, as a young adult, began to carry a chair and a jug of water into the garden and sit there, watching what his family thought were the birds. A standardised scale is unlikely to register this, although it tells a family something about what their son enjoys and can now manage on his own. Opportunities, and how a person spends the day, appear to play their part in how such skills develop.
Given that developmental changes may unfold gradually over many years, the timing of assessments may deserve as much attention as their content. What would it take for services to see someone a second time, and at what interval? When change is reported, how should a parent’s account be weighed against what an observation records? The answers will probably differ across services and across a person’s life, and the first assessment may simply be the first of several.
Where next
ACAMH Resources
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Best practices in autism assessment and intervention, Professor Tony Attwood discusses the process of designing a diagnostic assessment for children and adolescents with autism.
Tools for the process of assessment and diagnosis of Autism, Emma Woodhouse offers valuable insights into the assessment process of autism, viewed through the medical model.
Assessment and diagnosis of Autism: a guide for families, Emma Woodhouse offers valuable insights for parents who want to learn about the assessment process of autism.
Neurodiversity, autism and healthcare, In this talk, Jonathan Green presents a comprehensive framework for understanding the relationship between neurodiversity, autism, and healthcare delivery.
Developmental pathways in early autism, Professor Emily Jones delves into the realm of autism, a neurodevelopmental condition that affects approximately 2% of the population. Emily focuses on the significance of prospective longitudinal studies that track infants from early life to childhood, offering insights into the earliest developmental changes that precede the emergence of autistic traits.
Autism, Mental Health and Communication – Understanding communication differences in assessment, diagnosis, and support for autistic children & young people, In this talk, Ruth Fine highlights that autistic children and adolescents experience higher rates of anxiety, depression, and self-harm compared to their peers.
Mind the Kids – Autism Diagnosis: The Long and Winding Road, In this episode, Dr. Jane Gilmour and Professor Umar Toseeb unravel the complexities of autism diagnosis, shining a spotlight on the often-overlooked gender differences and the unique mental health challenges faced by autistic youth. With Dr. Miriam Martini.
Mind the Kids – Therapy and Autism: Actions for Adaptions, This Mind the Kids episode, ‘Therapy and Autism: Actions for Adaptations’, asks what does truly neurodiversity affirming therapy look like for autistic young people with co occurring mental health difficulties?
References
- Bal, V. H., Kim, S. H., Cheong, D., & Lord, C. (2015). Daily living skills in individuals with autism spectrum disorder from 2 to 21 years of age. Autism, 19(7), 774–784. https://doi.org/10.1177/1362361315575840
- Elias, R., & Lord, C. (2022). Diagnostic stability in individuals with autism spectrum disorder: Insights from a longitudinal follow-up study. Journal of Child Psychology and Psychiatry, 63(9), 973–983. https://doi.org/10.1111/jcpp.13551
- Gotham, K., Pickles, A., & Lord, C. (2012). Trajectories of autism severity in children using standardized ADOS scores. Pediatrics, 130(5), e1278–e1284. https://doi.org/10.1542/peds.2011-3668
- Grzadzinski, R., Carr, T., Colombi, C., McGuire, K., Dufek, S., Pickles, A., & Lord, C. (2016). Measuring changes in social communication behaviors: Preliminary development of the Brief Observation of Social Communication Change (BOSCC). Journal of Autism and Developmental Disorders, 46(7), 2464–2479. https://doi.org/10.1007/s10803-016-2782-9
- Jones, R. M., Carberry, C., Hamo, A., & Lord, C. (2017). Placebo-like response in absence of treatment in children with autism. Autism Research, 10(9), 1567–1572. https://doi.org/10.1002/aur.1798