Depends on your T. My first T was interesting... I had been seeing her for a while before I started seeing a pdoc. (She was the one who convinced me to see a pdoc and try medication.) Despite everything I told her, she literally said to me, "Bipolar?! I don't believe you're depressed. I don't think you've ever experienced depression before", even though I've had on-and-off suicidal thoughts since age 11. And this was a T who allegedly had "30 years of experience".

So, T's aren't perfect. Maybe your T is right and you are BP. Or, maybe your pdoc is right and you're *not* BP. Either way, an antidepressant will probably tell you if you're BP or not. Antidepressants usually worsen depression, cause a mixed state, or cause hypo/mania in BP people.