I was on fluoxetine when I was 16 and it did absolutely nothing. I had to go back on it (as it was the safest antidepressant for my heart at the time) when I was around 21. It was amazing. I'm on the highest dose now and I'm pretty sure it is one of the things that kept me going when things were truly dreadful in my 20s.
So yes. Worth a shot for definite.