Recognizing the Extent of Overlap Between Bipolar Disorder and Anxiety Disorders

The meta-analysis of prevalence of anxiety disorders among parespectively. Moreover, the utility of other medications, such as tients with bipolar disorder in this issue of E-Biomedicine (Nabavi et al., 2015) provides a timely summary of knowledge to date regarding this important co-occurrence of psychiatric conditions. The authors report that 43% of people with bipolar disorder have had at least one lifetime anxiety disorder. This figure is very similar to the 45% rate of people with bipolar disorder having had at least one lifetime anxiety disorder recently reported in a recent different metaanalysis, based on an only partially (less than half) overlapping set of studies (Pavlova et al., 2015). Individuals with bipolar disorder commonly have had more than one lifetime anxiety disorder. Indeed, the sum of the lifetime prevalences reported by Nabavi and associates for the individual anxiety disorders (panic disorder, generalized anxiety disorder, social anxiety disorder, post-traumatic stress disorder, specific phobia, obsessive compulsive disorder, and agoraphobia) was approximately twice as high (nearly 85%) as that for any anxiety disorder. Nabavi and associates' 43% meta-analytic lifetime prevalence rate of any anxiety disorder is slightly below the 48% mid-point between the lowest (17%) (Angst et al., 2013) and highest (79%) (Pini et al., 1997) lifetime prevalence rates reported in the individual studies reviewed, highlighting the substantial heterogeneity of anxiety disorder lifetime prevalence across samples. This important heterogeneitywas evident despite only including studies that used the rigorous approach of using interview-based diagnosis for comorbid anxiety disorders. As such heterogeneity likely has meaningful relationships with not only neurobiology but also clinical outcomes, researchers and clinicians alike need to account for anxiety disorder comorbidity in their efforts to understand, diagnose, and treat patients with complicated bipolar disorders. The very substantial percentage of bipolar disorder patients with a lifetime anxiety disorder has particularly profound clinical implications. Anxiety disorders and alcohol/substance use disorders commonly cooccur with one another and with mood disorders. Indeed, anxiety disorders and alcohol/substance use disorders constitute the two most commonly encountered comorbid conditions in people with bipolar disorder (Merikangas et al., 2007). As the authors point out, management of comorbid anxiety disorders in bipolar disorder patients with antidepressants and benzodiazepines may be limited by the risks of mood destabilization and exacerbation of substance use problems,