Am 61 and was taking Zocor for 2 1/2 months when I noticed that I could not tolerate normal exercise, had muscle weakness and and extreme fatigue. I later developed anxiety and finally depression and sought therapy. My psychiatrist and threapist told me that they have had a number of patients that also came in with depression who were taking Zocor. They said that they think that Zocor may be lowering certain brain chemicals that affect mood, thus causing depression. I decided to stop the Zocor and within two days the muscle symptoms and fatigue disappeared. I was also prescribed Lexapro to help with the depression. I am afraid to take Zocor ever again for fear that the whole syndrome I experienced will come back.