My sister is bipolar, and I think it's possible there's a little DP in there too. She was manic for a while and then had what she calls a "slide", when she crashed into a state of severe depression that she has been in ever since (several years now). She says that after the slide, her muscles lost all their tone. This happened very quickly, much quicker than it would take to lose it due to lack of exercise. She also says that her muscles seem to have lost their elasticity. If she exercises, it doesn't seem to build them up much. I have had DP for almost 20 years. The muscles of my lower body also seem to have lost their elasticity. My hamstrings are extremely tight but it seems impossible to stretch them without hurting myself, and some muscles have no tone--even in the past when I used to exercise them. Has anyone ever heard of or experienced anything like this in connection with mental illness?