I am a long term user of mirtazapine about seven years. I take it with a mood stabiliser lithium. Mirtazapine is an excellent anti depressant but it needs time to work at least six to eight weeks. The start up effects include incredible drowsiness which does wear off. Lower doses are usually more sedating than higher ones. It is a medication that needs to be taken consistently over a period of time to achieve a good result. Vivid dreams are a side effect of mirtzapine but again this settles over time. The only drawback for me of mirtazapine are the effects of withdrawal which can sometimes be very difficult to cope with.