The bipolar spectrum: diagnostic and pharmacologic considerations.

Bipolar disorder represents a clinically challenging, episodic, lifelong medical illness that is both disabling and dangerous to the patient and is associated with a high risk of suicide. The prognosis for bipolar patients is likely to worsen with delays in accurate diagnosis and treatment as time is allowed for more extensive complications and morbidity to accrue and for alcohol or other substance use comorbidity to complicate the course of the illness. Physicians face several challenges when diagnosing bipolar disorder, including overlapping symptomatology and comorbidity with other disorders, as well as the somewhat restrictive and categorical approach taken by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) and the International Statistical Classification of Diseases, 10th Revision (ICD-10) diagnostic criteria. As a result, bipolar disorder is frequently unrecognized and misdiagnosed with considerable clinical and prognostic consequences for the patient. The accuracy of diagnosis of bipolar disorder could be improved through the introduction of a refined procedure for the identification and evaluation of a broader range of symptoms, and by careful attention to the presence of subthreshold symptomatology. A conceptual shift toward acceptance of a 'spectrum' model of bipolar disorder and the development of appropriate clinical diagnostic tools should assist physicians in differentiating bipolar disorder from other Axis I, Axis II, and personality disorders, as well as ensuring early diagnosis and therapeutic intervention.