Mood disorder NOS (Not Otherwise Specified) is defined by the DSM is a more general category of mood disorders that do not fit the any other diagnosis. This diagnosis is used when it is difficult to choose between:

Agitation is a symptom of both depressive and bipolar disorders and may make it difficult to make a more specific diagnosis.

Mood disorders as diagnosed by the DSM edit
Mood episodes: Major depressive episode Manic episode Mixed episode Hypomanic episode

Depressive disorders: Major depressive disorder Dysthymic disorder Depressive disorder NOS (PMDD)

Bipolar disorders: Bipolar I disorder Bipolar II disorder Cyclothymic disorder Bipolar disorder NOS

Other mood disorders: Mood disorder due to a general medical condition Substance-induced mood disorder Mood disorder NOS

Episode specifiers: Severity Psychotic Remission Chronic Catatonic Melancholic Atypical Postpartum

Course specifiers: Longitudinal Seasonal (SAD) Rapid cycling