Description:

Bipolar disorder (formerly called manic depression) is a mental illness that exists along a spectrum. People with bipolar disorder have episodes of depression that alternate with periods of better mood.

In bipolar I disorder, these periods of better mood may involve mania: a high-energy state which can cause psychosis, extreme emotions like panic attacks, or euphoria. This feeling is often followed by a period of depression. People with bipolar I disorder switch between these two states.

In bipolar II disorder, a person never becomes manic or psychotic. Their episodes of depression are often longer and more severe, and they alternate with periods of hypomania. Other disorders on the bipolar spectrum include cyclothymia.