Bipolar Disorder, Type 1 is diagnosed when there is a manic episode that lasts 7 days or more, a manic episode that results in hospitalization, or co-occurring psychosis during the manic episode. Bipolar Type 1 often has associated depressive episodes, but it is not necessary to have a depressive episode to have the diagnosis. Bipolar Disorder, Type 2 is diagnosed when the subject has experienced a hypomanic episode as well as a full depressive episode. Hypomanic episodes last 4-7 days, or they can last longer but at a lower intensity than a full manic episode. A depressive episode is defined as a two week period in which the individual experiences severely low mood, poor sleep, decreased energy, decreased concentration, poor appetite, or suicidality, among other symptoms.