Diagnostic dilemmas and clinical correlates of mixed states in bipolar disorder.

Patients with bipolar disorder frequently have varying degrees of mixed states rather than pure episodic manic and depressive episodes. However, DSM-IV-TR and ICD-10 criteria do not fully account for patients' varying presentations; currently, there is no consensus on whether mixed states is a distinct, categorically different type of mania or whether it is a transitional state between depression and mania. Inconsistent diagnostic criteria can be problematic for clinicians when treating patients.