Mania and depression are the two major identifying signs of bipolar. Mania, or manic states, are marked by an extreme elevation in mood, energy, and activity levels. This can often manifest as reckless behavior, impulsive decision-making, and a decreased need for sleep. On the other hand, depressive episodes are characterized by feelings of intense sadness, hopelessness, and loss of interest or pleasure in activities that were once enjoyable. These episodes may also include changes in appetite and sleep.