Ask Lemmy

Sure, a person who gets shot in the head and loses part of their prefrontal cortex functionality could have "type 2 ADHD", and I suppose that if you otherwise similarly physically harm your brain using some chemicals in the same way that excessive sugar harms your pancreas you could develop the same condition. In fact I think meth usage would probably create a similar condition in the brain since long use of it causes you to be unable to produce serotonin/dopamine in the appropriate levels. But I seriously doubt that watching videos on your phone can cause it, any more than it can cause diabetes.

There are various attempts at categorizing ADHD, of various levels of scientific credibility.

The one I hear most often are "predominantly inattentive" and "predominantly hyperactive".

There are also quack psychology tests that break it down into basically zodiac signs.

Such distinctions can have their uses for clearer diagnostic pictures or educating people who need to handle others' ADHDs, but they're not nearly as important as they are in diabetes. They're arbitrary and they don't completely change the mechanism of the condition, as far as we're aware. It just doesn't affect much.

In short, there aren't really formal distinctions because it wouldn't be very practically useful to have them, and because it would be hard to agree on universal types.