YIKES! NO NO NO! MS is NOT a Psychiatric disorder! As someone with MS, I can tell you that is a very touchy subject with all of us!
MS is NOT related to muscular dystrophy. We may have tremors, but we don't see people with the spastic symptoms unless they have something else as well.
People need to be careful with the autoimmune as well, because AIDS is an autoimmune disease and they are not related.
MS is a NEUROLOGICAL DISEASE! Not PSYCHOLOGICAL! There is damage (lesions) on an MS Brain! Yes, MS is an autoimmune deficiency. People with MS can have a large variety of symptoms. It all depends on where the lesions are and whether they are active. There is so much on the internet that is incorrect, my doctors tell their patients to stick with the National MS Society for information. Here is a page from the National MS Society regarding diagnosing MS. http://www.nationalmssociety.org/about-multiple-sclerosis/what-we-know-about-ms/diagnosing-ms/index.aspx
Since there is no definitive test for MS, everything else has to be ruled out. Unfortunately that is why it takes so long and so many tests and time to get the diagnosis. Lyme disease can be ruled out by blood tests. Lupus has a test as well.
Good luck. If you have any questions, please let me know. I was diagnosed 6 yrs ago and now we think I had it for about 10 yrs before things became such a problem that we started testing. Testing took about 6 months. God Bless you.