The Diagnosis Process
From first step to results: what to expect from an adult autism assessment.
Total duration: 3-6 months (excluding wait time)
The actual assessment usually takes a few months. But the wait time before that can be six months to over a year. Expect a total of 9-18 months from registration to diagnosis through public healthcare systems.
The five phases
Referral & Intake
1-2 weeks active, months waiting
You start with your GP or primary care doctor for a referral to a specialist or clinic that does autism assessments. Some places accept self-referrals. The wait time starts here. Some clinics call for a brief phone screening to check if you're a good fit.
Tips
- Ask about the current wait time at registration
- Register at multiple clinics simultaneously
- Keep a folder with all correspondence
Questionnaires
1-3 weeks
Before your first appointment, you'll receive questionnaires by mail or online. Usually a general intake form and specific autism screening tools like the AQ-50 (Autism Quotient) or RAADS-R. Sometimes also forms about your childhood that a parent or family member needs to fill out.
Tips
- Take your time with questionnaires, don't rush through them
- Answer based on how you actually feel, not how you think you should answer
- If there's a form for parents: explain why this helps
Diagnostic Interviews
3-5 sessions over weeks
The core of the process. A psychologist or psychiatrist has conversations with you about your life, from childhood to now. They ask about social situations, sensory experiences, routines, interests, and how you handle change. Sometimes a family member is invited for a separate interview about your early years.
Tips
- Write down examples of situations you want to discuss beforehand
- It's okay to bring notes
- Ask for breaks if you need them
- You don't need to 'perform' or prove you're autistic
Observation & Testing (sometimes)
1-2 sessions
Not always part of the process, but some clinics use standardized observation instruments like the ADOS-2. This is a structured conversation with specific tasks. Cognitive tests may also be administered. This depends on the clinic and your specific situation.
Tips
- The ADOS isn't an exam, you can't fail it
- Behave as you normally would, not as you think an autistic person should
- When in doubt, ask beforehand what to expect
Results & Feedback
1-2 sessions
The evaluator discusses the conclusion with you. You'll hear whether you do or don't receive an autism spectrum diagnosis, and why. You also discuss what this means and what the next steps are. You'll receive a written report.
Tips
- Bring someone if you'd like support
- You don't need to understand or process everything immediately
- Ask for the report if you don't automatically receive it
Preparing for your assessment
Gather examples from your life
Think about concrete situations: moments you felt different from others, difficulty with social situations, sensory issues, intense interests. The more specific, the better.
Get info about your childhood
If you can ask parents or other family members about your childhood, do it. School reports, notes from previous professionals, even old diaries can help.
Be honest about masking
Tell them you've learned to adapt. Explain that during the interview you might come across as 'more normal' than you feel, because adapting has become automatic.
Prepare your questions
What do you want to know? About the process, about the diagnosis itself, about what comes after? Write your questions down so you don't forget them.
What if you don't get diagnosed?
Sometimes the evaluator concludes you don't meet the criteria. That might be accurate, but it could also mean the evaluator doesn't recognize autism well in people who mask effectively.
If you don't recognize yourself in the conclusion: ask for a second opinion. Look specifically for a practice with experience in autism in adults, in women, or in people with above-average intelligence.
And remember: a diagnosis changes nothing about who you are. Your experiences are valid, with or without paperwork.
Public vs. private assessment
Through public healthcare / insurance
- • May be fully or partially covered
- • Depends heavily on your country and insurance
- • Often long wait times (6-18+ months)
- • Usually needs referral from GP
Private / out-of-pocket
- • Cost: $1000-3000+ (varies by location)
- • Often not covered by insurance
- • Shorter wait times (weeks to months)
- • Check if diagnosis is recognized by employers/institutions