Bipolar disorder, particularly bipolar type I disorder, is at least as highly comorbid with other psychiatric and behavioral disorders as any Axis I medical disorder (Slide 1). Two iterations of the National Comorbidity Survey study, which is epidemio-logic-based and not anecdotal evidence from clinical offices and hospital emergency rooms, have shown that these data are reflective of the overall population in the United States and potentially for all other countries across the world.

In particular, if the prevalence rates of all anxiety disorders are grouped together, they are almost as prevalent as bipolar disorder itself, and clinicians rarely see a patient with bipolar disorder who does not have an anxiety disorder. This finding raises the question that anxiety may not be a separate entity, but an additional fundamental component of bipolar symptomatology, at least for a substantial number of patients. Regardless, the role of anxiety in bipolar disorder is unique. Perugi and colleagues studied the time sequence of different anxiety disorders in relation to first presence and clinical recognition of bipolar disorder (Slide 2). In contrast to panic disorder/agoraphobia and obsessive-compulsive disorder (OCD), social anxiety or social phobia was shown to be prevalent in 94.7% of patients prior to onset of hypomania and the clinically recognizable problematic school and home situations before the diagnosis of the bipolar disorder. This finding suggests that there may be some fundamental aspect of social anxiety and other anxiety disorders that is a ties. These patients tend to be more unstable symptomatically and have multiple comorbidities.