You are misreading what I wrote. I did not say that I thought it wasn't (at least not yet).
I asked if "legally" it is classed as one. There is a difference, as when it is classed "legally" as one, that brings entitlements (obviously) which the OP has hinted at with the kid on their street.
Although, whether or not it is a disability falls into the category of most mental illnesses (if you think they are a disability or not).
The legal definition of disability goes into more detail in that it would prevent a person from going about their normal life or prevent them from carrying out their job role - if it was that extreme, then yes it would be - but looking at many such cases it would appear that people who fall into this category have more than just one simple problem (e.g. ADHD) - they are presented with a whole host of medical/mental issues.
But if it's not to be a disability (as per the definition above), then it is just a bunch of ppl crying wolf trying to claim the benefits they can get out of it.
Isn't it interesting though that as usual, it originated from (no surprise) the USA.