200mg helped me a great deal for many years, but when I had a depressive episode a while back it was increased to 400mg. My Seroquel was also increased. I think if anything the Seroquel did the job, and I really haven't felt any difference (then or now) between 200 and 400mg. Only thing is that at that dose (as opposed to 200 which I took in the morning) my pdoc said some people get sleepy, so he told me to take it at night.