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How Late Is a “Late” ADHD Diagnosis?

You’ll often hear people talk about getting a “late” ADHD diagnosis. But how late do you have to be diagnosed for your diagnosis to be “late”?

This is definitely something that’s on a spectrum. Some late diagnoses are later than others.

For example, we could probably all agree that a diagnosis at age 55 could be considered late, as far as ADHD diagnoses go. But is a diagnosis at 40 also late? How about a diagnosis at 25?

LateI’d suggest that these are all “late” diagnoses – it’s just that some are later than others.

In fact, I’d consider any diagnosis in adulthood a late diagnosis. My logic behind this is that when you’re diagnosed as an adult, there’s a lot of unlearning you have to do, regardless of whether you’re diagnosed as a younger or older adult.

If you’re being diagnosed in adulthood, it means you’ve learned a whole way of relating to the world, organizing your life, and understanding yourself that is based on not knowing you have ADHD. Once you find out you have ADHD, you have to incorporate that new knowledge in the way you think about your life and your self.

There’s a good chance this means challenging a lot of negative assumptions you’ve built up over the years. If you’ve reached adulthood without an ADHD diagnosis, you might have come up with an alternative explanation for your symptoms, such as seeing yourself as incompetent or lazy. You might also have a string of failures and underachievement behind you. Accumulating all this psychological baggage of undiagnosed ADHD is what I’d consider the difference that makes for a “late” diagnosis.

The further along in adulthood you are, the truer this is. If you’re 25, it’s probably going to be easier to integrate the new insight you gain from an ADHD diagnosis into your life. This isn’t to say that doing so at 55 isn’t possible – it just might take more time and work since you’ve spent longer living with undiagnosed ADHD.

So if some late diagnoses are later than others, is it ever too late for a diagnosis? I think as long as you’re breathing, the answer is a resounding no.

Regardless of your age, chances are you can use the insights that come from an ADHD diagnosis to make changes in your life that will make you happier, improve your relationships and decrease your levels of stress.

I’d expect that the later you’re diagnosed, the more prone you’re going to be to looking back and wondering how things might have been different if you’d gotten diagnosed earlier. But an ADHD diagnosis can bring on an attack of the “what ifs?” at any age. The important point is that if you’ve been living up to this point without knowing you have ADHD, you almost certainly have areas in your life where you can benefit from the increased awareness that an ADHD diagnosis brings.

For this reason, I’m going to end this post by giving a contradictory answer to the question I posed at the beginning. On one hand, any diagnosis in adulthood is a late diagnosis. On the other hand, though, there’s actually no such thing as a late diagnosis because a diagnosis at any age is a new lease on life.

Image: Flickr/Shawn Campbell

How Late Is a “Late” ADHD Diagnosis?

Neil Petersen

Neil Petersen writes regularly on education, learning disabilities and technology. He received his B.A. in 2014 and was diagnosed with ADHD at the beginning of his college studies. Neil also works for a music education non-profit and hopes to help create an education system that can better serve students with ADHD.

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APA Reference
Petersen, N. (2018). How Late Is a “Late” ADHD Diagnosis?. Psych Central. Retrieved on April 24, 2019, from


Last updated: 19 Sep 2018
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