Hi Fuzzybear. This is an interesting topic. I'm only chiming in to emphasize that there is a "Bipolar Spectrum" concept, and within that there can be various presentations and degrees of mood fluctuations and other characteristics. I agree with earlier posters that a person could be on the bipolar spectrum without having had any notable hypomania/mania. The cycling must be considered. There are also situations where a person may have had one hypomania (or mania) in their entire lives that were otherwise solely consisting of depressions. One of the posters also mentioned that if a person responds better to moodstabilizers over antidepressants that perhaps that qualifies as bipolar spectrum. Likely psychiatrists and other experts have differing opinions, though.

It is important, I think, that when a person presents as "atypical" that differential diagnoses be explored. For example, Borderline Personality Disorder can sometimes be mistaken for bipolar disorder. Even some forms of anxiety...and other disorders. When I studied Abnormal Psychology these investigations were emphasized. Does the patient meet the criteria for another mental health disorder? How do they respond to certain medications? The latter, in the end, is among the most significant. We all like labels to explain what we're going through, but sometimes it's hard to put an exact finger on one. Then there are people who have never had a single depression that meets THAT criteria, but only a full-blown mania and only one in their lives. Those, too, can be on the spectrum.