Major Depressive Episode - At least 5 of the following symptoms, one of which must be depressed mood or loss of interest/pleasure, in the same 2 week period:
Loss of interest or pleasure
Feelings of worthlessness
Diminished ability to think or make decisions
Psychomotor retardation or agitation
Other symptoms: diminished sex drive, avoidance of other people, overwhelming feelings of sadness or grief
Manic Episode - A period of abnormally elevated, expansive, or irritable mood, lasting at least 1 week.
Mixed episode - Contains features of a major depressive episode and a manic episode nearly every day for 1 week.
Hypomanic episode - A period of abnormally elevated, expansive, or irritable mood, lasting 4 days, no impairment in social or occupational functioning.
Major Depressive Disorder - 2 or more major depressive episodes, absence of manic, hypomanic, or mixed episode
Test yourself on these definitions.