Guide
Create a written timeline of your child's developmental milestones: when they first smiled, babbled, pointed, walked, spoke first words, and combined words. Note any regressions or plateaus. Include details about pregnancy, birth, and early health. This information is critical for the diagnostician and is often difficult to recall on the spot.
Collect all previous medical records, developmental assessments, hearing and vision tests, speech-language evaluations, and school reports. If your child attended early intervention programs like Ontario Early Years or EarlyON, request any documentation from those programs. Organize everything chronologically.
Document specific behaviours that concern you across settings: home, school, community outings, and family gatherings. Note communication patterns, social interactions, repetitive behaviours, sensory sensitivities, and daily living skills. Use concrete examples with approximate frequency — diagnosticians find these details invaluable.
Ask your child's teachers, daycare providers, and other regular caregivers to write a brief description of your child's behaviour in their setting. Some assessment centres provide specific forms for third-party input. Different observers notice different things, and this multi-setting perspective strengthens the assessment.
Explain the assessment in age-appropriate terms. For younger children, you might say "We're going to visit someone who wants to play and talk with you." For older children, explain that the visit helps people understand how they think and learn. Visit the assessment site in advance if possible, or show photos. Plan for comfort items.
Assessments typically last 2-4 hours and may be split across multiple sessions. Ensure your child is well-rested and has eaten. Bring snacks, comfort items, and any fidgets or tools your child uses. Arrange childcare for siblings. Bring your documentation binder. Arrive early to complete intake paperwork.
Ontario Ministry of Children, Community and Social Services
Diagnostic assessment requirements for OAP eligibility (ontario.ca/autism)
College of Psychologists and Behaviour Analysts of Ontario
Standards for autism diagnostic assessment and qualified diagnosticians (cpbao.ca)
Written by Spencer Carroll
Founder & Autism Advocate
Evidence on this page
Key claims are paired with their source, evidence tier, and verification date so readers can inspect the public record directly.
Evidence supports autism screening and intervention commencing in the first 2 years of life — earlier identification directly enables earlier intervention during the highest neural plasticity window
1 in 50
According to the 2019 Canadian Health Survey on Children and Youth, about children and youth aged 1 to 17 in Canada had an autism diagnosis
WHO recommends accessible, community-based early interventions for children with autism — timely evidence-based psychosocial interventions improve communication and social engagement
89,799
children are registered in the Ontario Autism Program
23%
Only 20,633 children have active funding agreements — less than one in four