ADHD is a label, not a disease.

You can't really be diagnosed with symptom (although of course your money will be cheerfully taken to do just this).

Attention and focus and other related ADHD-type issues are bell curve.

It can feel good, for sure, to externalize our weakness and failings into one of these labels, like ADD. If that is helpful to get over the psychic weight of past failures, then that is helpful and useful.

Taking stimulants definitely helps most people with ability to work and focus, regardless of where they are on the attention-ability curve. There are also drawbacks and side-effects, at least I have observed.