Very possible,indeed. In fact,this happens so often,and docs hand out scripts for AD's, one common reason this happens is due to the fact if someone is hypomanic,feel great,chances are there is no reason to see a doc,but on the otherhand if a person is deeply depressed for awhile,it is not uncommon to seek help.
Bipolar as well as some other disorders do have variables,it's not "one size fits all" thus making misdiagnosis,something that happens often.
DJ, I just submitted my post at the same time as yours,please don't think you have an "echo".