Okay, I have tried to read through all 5 pages of replies with an open mind but sorry folks, many of you have shown your ignorance of mental health issues! Many if not all of mental health issues are caused by a chemical imbalance. If the antidepressent is correctly prescribed and it is a hit or miss deal, the person will not present in an "altered" state. Think about what we do, either paid or volly we are exposed to stressful situations, scenes that will be burned in our memories and many what if moments. Think about the soldiers that are coming back with PTSD. Their brain chemistry is altered from being in a constant state of flight or fight. Once they get treatment many of them are back to their pre-deploment state of mind.
I can think of one over prescribed drug that will cause a child to be a zomie, ritalin or any of its forms. If a person truly has ADHD/ADD that little pill is a life saver. For those kids that the teacher or parents think is too hyper and is medicated will present spaced out. ADHD is thought to be caused by low levels of dopamine in the frontal lobe. Medicate the problem, raise the levels and the person is "normal".
Now getting back to the original question. SSRI's, MAOIs can not be used as a prophylactic treatment. If you don't need the drug you are not going to see any benefits. It can actually make a person depressed, spacey, or a little off. I highly recommend the Physicians Desk Reference and the DSM-IV for your next reading assignment. Amazingly enlightening!!