The thing is, if you look at the diagnostic criteria for ADHD, nearly anyone could be defined as having it if they want.
No, that's not actually true, it's a myth, or you've only looked at part of the criteria. If you run screeners for ADHD on the general population, around 5-8% of people score as likely to have ADHD. If you run those screeners on people with diagnosed ADHD, it's more like 80-90%. (I apologise I do not have accurate numbers because I have ironically lost the ADHD textbook I was planning to check them in).
I'll skip the hyperactive criteria for a moment because they are a mess in adults, they were ported straight from the children's one and they are difficult to interpret because of that, the inattentive ones were too, but it's less of an issue - these are the inattentive criteria (from the DSM) - you need six of these.
- Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or with other activities.
- Often has trouble holding attention on tasks or play activities.
- Often does not seem to listen when spoken to directly.
- Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (e.g., loses focus, side-tracked).
- Often has trouble organizing tasks and activities.
- Often avoids, dislikes, or is reluctant to do tasks that require mental effort over a long period of time (such as schoolwork or homework).
- Often loses things necessary for tasks and activities (e.g. school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, mobile telephones).
- Is often easily distracted
- Is often forgetful in daily activities.
The "often" is significant; most people can identify with many of these problems some of the time, but it is not the same frequency as somebody with ADHD. In a screening questionnaire for example you would be asked something like "Lose items necessary for tasks and activities: Never, Rarely, Sometimes, Often, Very Often." It is only the items which are scored "Often" or "Very Often" which are considered significant. Most people would score themselves "Rarely" or "Sometimes" for most items on the list.
In addition, there is a requirement that the symptoms cannot be better explained by another disorder (such as depression), that they have been persistent for over six months, that they have been present before the age of 12, (so it's not just burnout from work/modern life) that they affect functioning in multiple settings, and that they are causing impairment.
Causing impairment, again, is significant. Everybody loses things sometimes. Who can ever find a pen? But that isn't an impairment, it's a minor annoyance. If you're constantly losing things that are expensive, hard to replace, that you need daily, that are essential, and you can't keep track of them despite following all the usual tips of trying to keep it in the same place, naming it etc - that's impairment.
Likewise, nobody likes studying or doing housework, but if you have actually failed multiple courses and are on the verge of being kicked out by your landlord because your house is disgusting and you literally can't make yourself do these things even though you have motivation and reason to do them - that's impairment.
It's not very well worded but doctors who are actually trained in assessment will know the difference between the normal "Well yeah housework is boring and effort" and "I literally can't make myself do it, I feel so worthless and I have no idea why nothing works"
So no, not everyone can fit into the diagnostic criteria of ADHD. Yes there are some silly things on tiktok etc, but if you're taking tiktok as the entire gospel truth, rather than entertainment or maybe a suggestion to look into some decent sources, then you're an idiot. Likewise, because ADHD is a current buzzword there are plenty of predatory companies that will prey on people's fears/curiosity and play up the mildest, most relateable symptoms in order to sell you a supplement or a subscription to an app or some kind of course or coaching service. But that doesn't mean that actual doctors who are diagnosing it are using those criteria to diagnose.