There's currently a government review of the Mental Health Act (MHA) 1983.
There are two surveys for mental health service users and for carers available through that page, which are closing in a couple of days. There will I believe be further chances to submit evidence over the next few months.
At the moment the Act follows the psychiatric establishment in seeing autism as 'disorder or disability of the mind'. This is elaborated in the current MHA code of practice, chapter 20. Addiction is excluded from the Act however (so to be blunt, the state can often try to stop you killing yourself, but not drinking yourself to death), and learning disabilities are excluded unless ''associated with abnormally aggressive or seriously irresponsible conduct'.
Some useful submissions already made:
Interesting but I don't have the time - I am not online at home or on my mobile - to complete the survey now. As you say lets hope there are further chances to submit evidence over the next few months.