I take it, and it is mainly to take the edge off of things. Essentially, it may be easier to visualize this. You have \/\/\/\/\/\/\/\/\/\/\ under normal conditions, but when taking Lexapro or a similar drug, your modds end up being more like ~~~~~~~~~~~~. (I know the graphics here aren't great, but you get the idea. It is usually used to keep someone from having big mood swings.
Side effects: Most of these drugs have sexual side effects, but they go away with time. In the short term, you may find that your sex drive will diminish, but over time this returns. delayed ejaculations may also be a result until your system normalizes again. That may take a couple of months. My guess would be that your doctor will prescribe you a low dose of 10mg or whatever the unit is. (ie. it may be micrograms or some other level, so spare the flames if I made an error) I was on 10 for awhile and was fine, but then the doctor put me on 20. (I honestly am not sure why he increased it, but I went with it) I was on 20 for awhile, then decided to go back to 10. My wife claimed she could tell the difference, but I think it was just because my body had not regulated the levels yet and things were out of balance during the transition. In any case, I went back to 20 and that's where I've been since.
The big thing with meds like this arfe that you should NOT SIMPLY STOP TAKING THE MEDICINE. Suddenly stopping medicines like these have been proven to lead to increased risk of suicide. You should gradually decrease use under a doctor's care so that you do not "crash" from the sudden change in the brain chemicals. In other words, you would go from ~~~~~ to ~\_________________/\/\/\/\/\/\/\