There are 184 combos, Well I dont know the exact number lol
"Usually" Pdoc's like to toss people on some type of Mood stabilzer. Since your more on the depressive end Lamictal could be a good possibilty.
Finding the right med(s) that will work for you will take patience and time, Its almost unhead of finding the right ones the first go around.
Best advice read up on the most commonly prescribed medications and get a working knowlege of them,, AD 's AP's AAP's, mood stabilizer, lots of seizure medications are used for Bipolar off label. I actully like the website Crazymeds.com ... its a good site with easy to understand side effects and a bit of humor, might as well get a chuckle here and there. Lots and lots to learn.. You will find PC is a wealth of information.