Case studies on the evolution and challenges in ASD diagnosis

Although the literature suggests that autism spectrum disorder (ASD) remains relatively stable over time, the variability in symptom presentation can make accurate and timely diagnosis challenging. This retrospective case study presents two illustrative cases that highlight the complexities of diagnosing ASD with different clinical presentations. Using respective data, two patients underwent multiple diagnostic evaluations utilizing autism-specific instruments, including the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) as well as other developmental assessment measures. Case 1 presents a male patient who was evaluated at 2 years of age and again at 9 years of age. Case 2 describes a female patient who was evaluated at 4 years of age and again 8 years of age. Notably, each evaluation resulted in different diagnostic impressions for each patient. The first patient received an early ASD diagnosis, but subsequent evaluation did not support the continued presence of sufficient symptoms to warrant the diagnosis. Conversely, the second patient did not receive an early ASD diagnosis but met criteria for the disorder upon follow-up evaluation. The case studies emphasize the complexity of diagnosing ASD given a range of issues such as symptom variability in presentation and severity, gender differences, broadening diagnostic criteria, changing diagnostic tools, and treatment response. These cases illustrate that periodic, comprehensive assessments are vital for accurate diagnosis and tailored interventions. Experienced clinicians and refined diagnostic tools are essential for supporting individuals with ASD and their families, ensuring responsive and effective care throughout their development.