I had been taking 50 mgs of Zoloft and my doctor raised my dosage to 100 mgs, she did this to take me off xanax, which I had been on for 12-15 years, I was taking 2mg at bedtime to calm me down so I can sleep. I am now having tremors and involuntary muscle movements, always occuring through the night, and can't sleep now until the wee ours of the morning,