In DSM-II, this category is called Other major affective disorder (Affective psychosis, other)
Major affective disorders for which a more specific diagnosis has not been made are included here. It is also for "mixed" manic-depressive illness, in which manic and depressive symptoms appear almost simultaneously. It does not include Psychotic depressive reaction or Depressive neurosis.
This category includes disorders with mood symptoms that do not meet the criteria for any specific Mood Disorder and in which it is difficult to choose between Depressive Disorder Not Otherwise Specified and Bipolar Disorder Not Otherwise Specified (e.g., acute agitation).