I feel at my worst at night as well. I'm sure for a lot of people there is something inherent about the darkness. For me, my depression is linked a lot to stress and feeling that I am not able to cope, so I think that at night my mind just hooks on to that more.

I usually feel best right when primetime tv starts. Very often I feel very very lousy in the early evening, almost unable to function at all, but if I can make it to 8:00 I can hook onto TV for the next few hours and get by, even if my mind is racing on other things. Not the healthiest of activities but it gets me through.

Then once bedtime comes the mind just starts racing. Currently I am taking Lunesta to help me sleep and it does seem to work, at least it gets me through the night.