Given the life experiences of many autistics, I would wonder if you could have high-functioning autism without being clincally depressed and/or post-traumatically stressed.
Depression is definately a will-sapping thing. It easily creates feelings of overwhelm when it comes to larger tasks, or even some small, routine tasks. One of the reasons 12-step groups use the slogan "one day at a time" is that routine activities can seem overwhelming when they're given a time-scale unbounded by limits other than death. E.g., brushing one's teeth... twice a day... every day... for the rest of your life.
