Across several public healthcare systems, demand for ADHD and autism assessment has grown faster than assessment capacity, driven by rising referral numbers, wider public awareness of both conditions, and a limited pool of clinicians trained to conduct these specific assessments. The result, reported widely in the UK, Canada, Australia and Ireland among other countries, is waiting times that can run from many months to several years, depending on region and service.
What this means in practice
A long wait is not a reflection of how significant your difficulties are; it reflects system capacity. While you wait, some people choose to pursue a private assessment to get a formal diagnosis sooner, others use the waiting period to gather supporting evidence such as school reports or a symptom diary, and some remain on the public list because cost or eligibility rules make a private route unsuitable for them. All three are reasonable choices, and none is a judgement on the person waiting.