No, the usual retort is the argument that "everyone experiences this" is irrelevant.
It's the degree to which a person experiences it, and the impact it has to their life is what is relevant.
Same as how everyone forgets things sometimes, but not everybody has dementia.
Or how everyone oversleeps sometimes, but not everyone has narcolepsy.
Not to mention that "struggling to focus and procrastinating often" is just one aspect of ADHD. There are also sensory issues, stimming, over-fixations, memory issues, and several other things.
>Whoa, that's a lot of people! 1 in 20 people
Other mental and body issues have even bigger spread. Doesn't mean they don't exist. Check how many people are depressed (way more than 1 in 20), whether they take drugs for it or not.
>the authors state that “no biological marker is diagnostic for ADHD” and that “meta-analysis of all neuroimaging studies do not show differences between individuals with ADHD and control subjects”, thus “no form of neuroimaging can be used for diagnosis of ADHD”.
Yes. Several diseases are like that.
Not everything boils down to "you lack this protein in your system" or "your heart has a blocked artery" that can be seen trivially. Some diagnosis require observation and nuance, instead of a mechanical test, who would have thought?
Some issues occur because of developmental issues in brain connectivity and which brain "modules" overwork or underwork. Those aren't things that show up in blookwork or X-rays. That said, some of the results of that can be seen in brain scans of ADHD vs regular brains, even if we don't know the exact cause of ADHD.
In any case, for most diseases we first see the symptoms and learn to identify them, them later we might be able to find some way to aleviate them, then find some pathways and perhaps ways to cure them even if we don't understand the mechanisms entirely, and only after centuries or decades or research (if we're lucky), we might pinpoint the exact mechanisms. For many medical issues we have neither cures not understanding of causes - that's even for very frequent and impactful issues.
You seem like you gave the thing a few days worth of thought (not necessarily just a few days of actual calendar time, just a few days worth of though), and decided you have the right idea, and others are stupid or in it for profit.
I suggest you go live for a good while with someone who has ADHD and see if what they have is just them "struggling to focus and procrastinating often" they same way every Average Joe "experiences it sometimes", and whether they're just "addicted to their phone".