Not the exact definition, but is aok
Maybe.
The stress and depression should diminish. The pills will also, in most cases, help with the OCD that many autists have to a certain degree. During a depression the OCD will usually get a lot worse, but luckily it is the same pills.
I assume you mean that the cause will not be resolved, and not the symptoms will not be resolved.
I would agree with that, though it can go away on its own in a some 5-10 years(depending on how hard it is and what age one is. But with a fairly decent case in the early 20's, which gets nothing but SSRI medication would probably be able to cope without medication by 30.)
What i am saying here is a vague generalization, it is not scientificly accurate in neither description of the depression nor the timeframe, but is solely used to show that things usually do improve on their own by themselfes.
Sincerely
Tobias