As a counsellor working with neurodivergent adults, and someone who was diagnosed with AuDHD later in life myself, I’ve heard most of the reactions people have when someone shares a new autism or ADHD diagnosis.
Almost all of them come from good intentions.
Very few of them land the way they were meant to…
When someone trusts you with that news, the pressure to say exactly the right thing can feel enormous. But here’s the relief: you don’t need a perfect response. You mostly need to avoid a handful of common mistakes.
The first is disbelief dressed up as a compliment: “but you don’t seem autistic,” or “I never would have guessed.” Adults diagnosed later in life have often spent years learning to camouflage traits that would otherwise be visible, a pattern researchers describe as masking or social camouflaging (Hull et al., 2017). Not being noticed isn’t evidence that something was mild. More often, it’s evidence of how much effort went into making it invisible, to colleagues, to friends, sometimes even to themselves.
The second is minimising: “everyone’s a little bit like that” or “we’re all on the spectrum somewhere.” It’s rarely meant to dismiss, but it does. A diagnosis isn’t a personality quirk. It follows a formal assessment against clinical criteria, and for many people, it’s the first time a lifelong pattern of struggle finally has a name.
The third is suspicion: wondering aloud whether someone pursued a diagnosis for the supports or financial assistance that can come with it, or whether they’re “too old” for a diagnosis to mean anything now. Needing formal recognition to access support isn’t a loophole. It’s how the system works for every diagnosis, not just this one.
The fourth is treating someone differently once they start unmasking, then criticising them for it: “you seem more autistic since you got diagnosed.” That’s often the whole point. Learning to drop a lifetime of compensating is progress, not a problem.
The fifth is making it about you: sharing your views on diagnosis in general, or explaining why you’re not sure labels are necessary. None of that is what the moment calls for.
What actually helps is much simpler. “Thank you for telling me” gives the moment room to land. Genuine curiosity, “what’s that been like for you”, invites someone to share as much as they choose, rather than assuming you already know what it means. And it helps to remember the diagnosis didn’t create anything new. The traits and the coping strategies were already there. A diagnosis simply gives someone language for what they may have been carrying quietly, and often alone, for a long time.
Late diagnosis, particularly in adults and especially in women, has become far more common as understanding of autism and ADHD has broadened beyond the narrower, often male-centred presentations that shaped earlier diagnostic criteria (Lai & Baron-Cohen, 2015). For many, it arrives less as a shock and more as a relief: finally, an explanation that fits.
If someone shares that news with you, you rarely need many words. Thank them for trusting you, listen carefully, and leave your opinion about the diagnosis out of it entirely.
References
Hull, L., Petrides, K. V., Allison, C., Smith, P., Baron-Cohen, S., Lai, M. C., & Mandy, W. (2017). “Putting on My Best Normal”: Social Camouflaging in Adults with Autism Spectrum Conditions. Journal of Autism and Developmental Disorders, 47(8), 2519–2534. https://doi.org/10.1007/s10803-017-3166-5
Lai, M. C., & Baron-Cohen, S. (2015). Identifying the lost generation of adults with autism spectrum conditions. The Lancet Psychiatry, 2(11), 1013–1027. https://doi.org/10.1016/S2215-0366(15)00277-1