Bipolar Disorder, formerly known as manic depression, is a mental illness that causes shifts in your mood, energy, and activities. There are two types of Bipolar: 1 and 2. The main difference is the severity of the manic episodes. Type 1 is more severe than two, and these clients usually end up being admitted to a psychiatric hospital. Type 2 is sometimes referred to as hypomania. Both should be treated seriously because type 2 usually leads to longer periods of depression.