The funny thing is that if you take a bunch of different antidepressants then you will become bipolar.. perhaps.
Then you need more and different medications.
Then you need more and different medications.
It's true that some antidepressants tend to shoot a bit over the target, but that can be easily taken into account. One such "manic episode", which isn't really called as such because it is drug-induced, doesn't make a bipolar disorder.