I've been on Zoloft 11 years alternating between 50 - 75 mg. Thi...

I've been on Zoloft 11 years alternating between 50 - 75 mg. This SSRI positively changed my life. From being depressed/anxious/obsessive compulsive I've managed to lead a full happy and productive life. HOWEVER, the last three nights I've experienced terrible anxiety producing nightmares. Waking up shaking and with my heart pounding, I'm wondering if changing from Zoloft (brand name) to a genertic would cause this problem. I switched three months ago without any problems. Has anyone experienced the same symptoms, and if so, had you switched to a generic? It seems these nightmares would have occurred sooner if that was the problem.