Activated depression: mixed bipolar disorder or agitated unipolar depression?

The combination of depression and activation presents clinical and diagnostic challenges. It can occur, in either bipolar disorder or major depressive disorder, as increased agitation as a dimension of depression. What is called agitation can consist of expressions of painful inner tension or as disinhibited goal-directed behavior and thought. In bipolar disorder, elements of depression can be combined with those of mania. In this case, the agitation, in addition to increased motor activity and painful inner tension, must include symptoms of mania that are related to goal-directed behavior or manic cognition. These diagnostic considerations are important, as activated depression potentially carries increased behavioral risk, especially for suicidal behavior, and optimal treatments for depressive episodes differ between bipolar disorder and major depressive disorder.