Duloxetine
"I'm very treatment resistant bipolar type 2, typically severely depressed, with OCD and several other comorbid diagnoses, and antidepressants for me, IF they work, will tend to poop out after only a few weeks to a few months. This was not the case for duloxetine. I started on 60 mg and it worked wonderfully for several months, the longest any antidepressant has worked for me. Then, that summer, I became depressed again. After trials of other meds, I wound up back on duloxetine, this time at 90 mg, which worked for another 6 months. I begged for 120 mg but for some reason my psychiatrist refused to prescribe it, so I had to switch to something else. Recently I wound up back on it for about a month or so at 120 mg, then at 80 mg."