I have been on several anti-depressants over the years, starting about 15 years ago. I started with Paxil, went through several others, and am now on Cymbalta. For many years I was diagnosed as having a depressive/anxiety disorder. Anti-depressants would work somewhat for a period of time. By somewhat I mean they at least controlled the suicidal thoughts I was having.
About 3 years ago my Dr. reassessed my depression and asked me some more in depth questions. They related to my sleep patterns, energy patterns, spending patterns, interests in activities, mood as well as several other things. The diagnosis was Bi Polar type II with PTSD Since then I have been treated with not just the anti-depressant, which keeps my depression at bay, but also a mood stabilizer. The mood stabilizer keeps me from having drastic changes. I think of it like a pendulum swinging. Before the mood stabilizer the pendulum made big arcs now it still makes arcs but not as dramatic. It does not make me feel high, drunk, or stoned. I did have to try several of them to find the one that works for me. I started on Lithium and now take Lamictal. Lithium left me feeling zombie like and drugged as well as causing a significant weight gain. The only thing I notice with the Lamictal is I can tell when I miss a dose as I get the urge to spend money.
You might try taking the test at this link
http://psychcentral.com/quizzes/bipolarquiz.htm it might help answer some of your questions.
Do remember that many mental illnesses can be treated quite effectively but we have to do our part by advocating for ourselves with our MD's. The MD is only as good as the information we give them. Good luck.