Your meds aren,t working then and you need sleep or your body won,t function properly.Also,you said you take meds for depression so depression and stress can keep you awake,so can bi-polar.When i was depressed the only meds that helped me sleep were the benzo,s like valium.I had to increase the dose because eventually you body gets use to it and the effect of the drug becomes weaker.If you want to go natural there are plenty of foods that help with sleep,google them.All the best.
Are you bipolar? Iam and that's part of it (insomnia) and my sleeping pills don't work either they have to keep upping my meds that's just part of it something you kinds have to live with
Try Thryptophan. It is a natural mood enhancer so ask the doctor if it will react with your other drugs before taking it. I have gone off all my depression drugs and am now only on the Thrypto. :) Lovin it.