PE4.2 | Autism Spectrum Disorder — Summary & Reflection

KEY TAKEAWAYS

ASD is a neurodevelopmental disorder defined by two DSM-5 domains: (A) persistent deficits in social communication and interaction (social-emotional reciprocity, nonverbal communication, and relationships — all three required), and (B) restricted repetitive behaviours (stereotypies, insistence on sameness, fixated interests, sensory reactivity — at least two required). Both domains must be present.

Aetiology: multifactorial — heritability 64–91% (polygenic; de novo mutations in SHANK3/CNTNAP2/CHD8; syndromic: Fragile X, tuberous sclerosis, Rett); neurobiological (social brain network atypicality, E/I imbalance); environmental modifiers (prenatal valproate, advanced paternal age, prematurity). MMR vaccine does NOT cause ASD.

Diagnosis: clinical, using ADOS-2 + ADI-R. Screen with M-CHAT-R/F at 16–30 months. Levels 1–3 by support requirement. Comorbidities are the rule: ID (30–50%), ADHD (30–50%), epilepsy (20–30%), anxiety (40–50%).

Management: early intensive ABA + speech therapy + OT + special education + parent training. No medication treats core ASD. Risperidone/aripiprazole for irritability; methylphenidate/atomoxetine for ADHD comorbidity; melatonin for sleep. RPWD Act 2016 + National Trust Act 1999 for entitlements. Start therapy immediately — do not wait for diagnostic confirmation.

REFLECT

Return to Aarav from the opening scenario. His mother asked whether the MMR vaccine caused his autism. You now have the knowledge to answer her clearly and compassionately — but how will you say it so she hears it rather than feeling dismissed? And beyond the MMR question, consider the weight of what you will say next: this family is at the beginning of a long, difficult, and often remarkable journey. What would you prioritise in the first 10 minutes of that conversation? What referrals would you make today, before the diagnostic workup is complete? And when you imagine Aarav at age 12 — what does 'a good outcome' look like for him and his family, and what role does the early clinical encounter play in making that possible?