Bipolar disorder is a severe mood disorder characterized by unpredictable and dramatic mood swings between the highs of mania and lows of depression. These mood episodes occur among periods of 'normal mood', termed euthymia. Prior research has clearly shown that brain emotion circuitry is dysregulated in individuals diagnosed with bipolar disorder. It is thought that these disturbances impair one's ability to control emotion and contribute to mood episodes. Investigators have now used functional magnetic resonance imaging (fMRI) to investigate which areas of the brain showed abnormal activation while patients in different mood phases of bipolar disorder tried to control their response to emotional and non-emotional material.