I agree with what Annie said above - many people with AutoImmune disorders are severely low on Vitamin D. You might want to ask your doctor to run a few blood tests on you to test your Vitamin/Mineral levels, and also to test you for Celiac Disease.

Many people with MG have issues with gluten (whether or not they test positive for Celiac), and find that many other problems disappear when they eliminate it from their diet.

I was diagnosed with CD first, the MG came later. When I went gluten-free, a lot of my depression issues went away. (I still take Prozac, but it's a relatively low dosage, and I haven't had any side effects to speak of) It has to do with absorption of nutrients - if your body isn't absorbing everything you are taking in, it WILL take what it needs from wherever it can find it.

There's lots of info about Celiac and gluten-free eating on the web.