I know that is mostly for clinical depression, and is hardly used with Bipolar Disorder, that usually requires a mood stabilizer as the main med. which there are several of those types too.
Before my being diagnosed with Bipolar-II, which most BP-II's suffer more from depression than mild mania, my GP had tried every SSRI (selective serotonin reuptake inhibitor), wellbutrin and then effexor.
For a short time they helped, but extreme stress brought out the BP, which I am genetically wired for, my oldest brother is BP-I, and there have been others that back in their day were never Dxed but today would meet the criteria for this disorder when hearing of their behaviour and events.
I had one great, great uncle that back in his day (early 1900's) had commited suicide, some say it may have been an accidental overdose of sleeping pills, due to his age, he was in his early 70's. Oh enough of hearing of my stuff, I am sure you have your own problems, that you may be dealing with.
If you are being treated by a GP for depression, I would suggest if it is not working after awhile it would be best to be evaluated by a pdoc, they are the specialists in this area, and could help you get the proper, effective med/treatment.
Life is short and it isn't worth having to suffer with things that can be helped, even if it means taking a med, giving you a better quality of life. . . just my opinion based on my personal experiences.
Whatever it is, I wish you luck with this, and please feel free to always drop by the forums or even check if anyone is on "chat", that is fun to do and helpful too

Take care now,
DE

In giving advice seek to help, not please your friend
SOLON