Is it Lexapro?
I am on it at the moment it that's what you mean. It just stabilises the ups and down. The first week I had some weird side effects - felt like I was on speed - everything moved to slowly for me and then it settled down. Love how I feel at the moment (been 4 months) but that's me coming to the end of the depression as well as the meds.
Have a look at the other threads... there are a few about Lexapro.