Diagnostic status of bipolar II disorder

Recent years have seen the expansion of the concept of bipolar disorder. In particular, two main diagnoses have been defined within DSM V. These are bipolar I (BD I) and bipolar II disorder (BD II). The former manifests with both depressive and manic episodes. The latter is characterised chiefly by depressive phases and at least one hypomanic period. A similar distinction was later made within ICD 11, which expands the description of BD II, briefly mentioned by ICD 10, its predecessor. The argument presented here is that these are really one and the same condition and the distinction between them is largely meaningless.