First of all, there is no clear consensus as to how many types of bipolar
disorder exist. In
DSM-IV-TR and ICD-10, bipolar
disorder is conceptualized as a spectrum of disorders occurring on a continuum. The DSM-IV-TR lists four types of mood disorders which fit into the bipolar categories: Bipolar I, Bipolar II, Cyclothymia, and Bipolar Disorder NOS (Not Otherwise Specified) like I said, so I was in fact numerating the aknowledged types only, yet articles tell you there are even more than 5.