Mania (from Greek μανία[1] and that from μαίνομαι - mainomai, "to rage, to be furious") is a severe medical condition characterized by extremely elevated mood, energy, unusual thought patterns and sometimes psychosis. There are several possible causes for mania including drug abuse and brain tumours, but it is most often associated with bipolar disorder, where episodes of mania may cyclically alternate with episodes of major depression. These cycles may relate to diurnal rhythms and environmental stressors.