Can you cure Parkinson's with positivity

My wife and I have been having an ongoing debate as she feels that my depression makes it hard to heal and that you can cure anything with a positive attitude. I said that you can cure diseases like cancer with a positive attitude because the immune system can fight cancer but that Parkinson's is medically incurable. I believe in God so I said that God Can Heal Parkinson's ( there are several known cases on youtube) but that it's medically incurable. I said there are certain people who overcome parkinson's to some extent with exercise and diet but they all still have some symptoms and have not been cured.
See thinks I'm talking rubbish and that this doesn't make any sense.
So I'd love the community's input. Is Parkinson's medically incurable or can I completely cure myself with positive thinking?