Rowan,
I used antidepressants off and on during my thirties and early forties, basically for PMS symptoms and they worked great. Back then that treatment was unheard of and scoffed at. I used low doses and for half of the month. Once in while I used xanax...usually one pill per month.
Over several years my drs & I tried just about everything else in order to give me the best care. I prefer good old Prozac and/or Zoloft, and my mood would improve in a day or two and continue to improve for up to two weeks.
Although the research does not back this up...many women- including me have extreme problems with hormone levels. For this reason my dr gave me oral (rxs) and topical (otc)progesterone and as my needs evolved I ended up using a micronized progesterone in the form of a birth control pill!
I had frequent blood tests done to examine the hormonal balance and for about a year I used bioidenticals formulated just for my needs. It may sound complicated but I am condensing about 15 years of my history here.
I was very fortunate to have a GP and GYN who were willing to experiment and treat me a person instead prescribing some cookie cutter treatment. (I was a good guinea pig for them!)
So basically...only if my moods got to the point where things got scary for me did I use anti-d's and the last time I tried one...it did absolutely nothing for me. I later found relief by using HRT, but not the kind that was used in the Framingham studies and found to be harmful.
Of course this is just my individual example but I do know of many women-where finding hormonal balance is key to having stable moods. And one thing that I always did was to stay under the care of a physician (or two) instead of diagnosing and treating things myself with the natural progesterone cream that I used. It's funny that the name on the label of that cream included the word "happy" which was not false advertising!!
Good luck and I hope you find a way to feel your very best, soon.