0 Borderline, feels like I'm going to lose my mind.....thanks, Madge

I'm having a brain fartage weekend where the grey matter has apparently gone on holiday without me.
Got a question, though, to ask all you lovely readers -
Where does autism stop and mental health begin?
Cos I get the whole anxiety disorders, OCD et el are part and parcel of the Spectrum - heck, the level of extra bonus' offered on the Spectrum you'll never see at David Jones or Myers - but where/when exactly does it become mental health?
I ask as a disability service stated they didn't cater for mental health issues, only disabilities.
You and I could sit here until the cows come home discussing how mental illness can be a disability in itself but autism is clearly defined as a 'disability' and a 'mental illness' in some circles.
Soooooo....how abouts them OCD quirks? Disability?
Nahhhhh.
Anxiety higher than the Great Wall of China (and better at keeping rabbits out)? Disability?
Nope.
These aren't disabilities in themselves until they grow to the point where they block activities of daily living.
But they are quite readily found, and accepted, on the mental health side of the ledger.
Autism isn't classed as a mental illness yet it's catered for in many such areas as Child and Adolescent Mental Health service, Mental Health Australia, etc.
Some ASD specific places encourage the implementation of a mental health care plan.
So....when does Autism cross the border into mental illness and when do we get the memo that the whole stigma of mental illness is behind us?