Determined Unconditional Love.
My eldest daughter although not moody had a lot of difficult stuff in her life. A stepfather, new siblings and a birth father who had major life controlling problems.
We tried always to answer each challenge with unconditional love and understanding. I found a great way to get her to talk and open up was on long drives. Later I discovered that this is a conflict management tool sitting side by side opens discussion and removes conflict. It would usually be at the end of the drive the talk would come.
I also had a good friend who loved my daughter and I would ask her to talk to Faith saying I think this is the problem. I was usually right. Faith would be much better just from talking to a safe adult who cared and wasn't her mother.
I never forced the issue or made her talk to me, now she talks to me about everything and has grown into an amazing woman.
I also demanded and gave good manners. It doesn't matter what you feel like you can still treat others properly.
My son also is aspergers and has epilepsy when he went to a Psychologist at 16. His Psychologist said he had never met a child with aspergers who didn't have anger issues before.
I believe it is that determined unconditional love that always works for the best for your child and believes that everyone has a purpose and a reason for their life. sorry this is a bit long, I think I should make a hub. hope it helps.