Hello, You have been on Zoloft (Sertraline) for many years and with high doses. This means that you cannot stop taking this drug because you body and your brain needs it. Stopping sertraline abruptly may result in one or more of the following withdrawal symptoms flu like symptoms, irritability, nausea, feeling dizzy, vomiting, nightmares, headache and insomnia. Even only missing a dose of sertraline may increase your risk for relapse in your symptoms. If you feel that your depression symptoms are not getting better with your actual depression medicines, my advice for you is to consult physically your treating psychiatrist as soon as possible because you may need a change in your depression medications. I also suggest to insist with your psychotherapist, to try light therapy, meditation and participate to enjoyable activities. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Elona Xhardo, Endocrinologist