Interesting that this discussion has come up again now. Haven't been able to read the thread properly as I'm still shaking and anxious, I've just had a terrible experience with an SSRI after going to the doctor asking for help with anxiety and OCD. She prescribed fluoxetine 20mg (which is the generic version of Prozac). Could feel it doing something on the first day, and it didn't feel good. Continued for three days and side effects got much worse, nausea, tiredness, confusion, whole body began to itch & some involuntary tremors. Anxiety was ramped up tenfold. But stupidly thought that these were just normal side effects so continued for four days more... at which point I couldn't get out of bed, too sick to walk or eat and feeling very dizzy and poisoned. I assume it was some form of serotonin syndrome:
http://en.wikipedia.org/wiki/Serotonin_syndrome
Now it's been five days since I stopped and I've been in bed on average 18 hours per day. Unable to do anything but sleep. Weird dreams, nightmares & the whole bit. I'm feeling a bit more awake today, but the tremor & anxiety have increased. I assume this is an effect the serotonin draining from the body. Hopefully I'll be back to my "normal" (not very good) state in the next two weeks. Keep thinking I've been permanently damaged but I know that feeling of 'dread' is probably down to the dysphoria the drugs induced.
So all in all a disastrous experiment. I should've known I had problems tolerating serotonin, I had similar problems (tho nowhere near as bad) with St John's Wort which is pretty mild as far as SSRI's go. I assume my body just can't process serotonin effectively. Seems like I've got too much or I'm not getting rid of it fast enough if anything.
The whole process of me being diagnosed and getting prescribed fluoxetine took less than five minutes. My GP diagnosed me and chose the treatment by looking in a book, which had a small passage about each SSRI. No further explanation apart from: 'this will help you. give it three weeks, if it doesn't work, come back in a month'.
Also, the notion that antidepressants work by (just by) increasing serotonin is highly speculative. There are case studies of people with no serotonin at all that aren't depressed:
http://neuroskeptic.blogspot.com/2010/03/life-without-serotonin.html -- prozac increases serotonin from day one, but the antidepressant effect usually take around a month to work, which is about the time it takes for neurogenesis to kick in:
http://neurologicalcorrelates.com/wordpress/2009/02/24/stoned-and-stupid-blame-your-microtubules/ -- it's possible the increased brain plasticity allows you to see life differently and change your negative thought patterns.
There are other ways to promote neurogenesis including exercise, bright light, learning & certain foods/supplements (i.e. circumin from turmeric) may also help. This makes sense, many people report feeling better after increasing exercise, exposure to sunlight and so forth. Exercise immediately releases dopamine/serotonin, but the culminative effect on wellbeing many experience may be due to neurogenesis.
So I suppose I'll be focusing on 'natural' ways to change my thought patterns, which I was doing anyway, but now it's the only game in town for me, unless anyone knows of an anti-depressant that doesn't increase serotonin?
Also, agree depression is caused by genes x environment. But environment can generally override genetics. (Switch off genes etc, correct me if I'm wrong). A study I saw recently shows that East Asians are probably more likely genetically predisposed to depression, but the incidence of depression is in fact much less than in the U.S, probably due to the increased social support and sense of belonging people have. I'm too jumpy to find this study now but hopefully continue discussion when i feel better.