Peer-review started: September 30, 2018
First decision: October 17, 2018
Revised: November 4, 2018
Accepted: December 5, 2018
Article in press: December 5, 2018
Published online: January 4, 2019
Over the last three decades burgeoning research has shown that anxiety disorder comorbidity is not only highly prevalent in bipolar disorder (BD), but it also adversely impacts the course, outcome, and treatment of BD. The present review provides an overview of the current trends in research on comorbid anxiety and BDs based on prior reviews and meta-analyses (n = 103), epidemiological surveys, and large-scale clinical studies. The results reiterated the fact that at least half of those with BD are likely to develop an anxiety disorder in their lifetimes and a third of them will manifest an anxiety disorder at any point of time. All types of anxiety disorders were equally common in BD. However, there was a wide variation in rates across different sources, with most of this discrepancy being accounted for by methodological differences between reports. Comorbid anxiety disorders negatively impacted the presentation and course of BD. This unfavourable clinical profile led to poorer outcome and functioning and impeded treatment of BD. Despite the extensive body of research there was paucity of data on aetiology and treatment of anxiety disorder comorbidity in BD. Nevertheless, the substantial burden and unique characteristics of this comorbidity has important clinical and research implications.
Core tip: This review of existing research shows that about half of those with bipolar disorder (BD) are likely to develop anxiety disorders in their lifetimes and a third of them will manifest these disorders at any point of time. Anxiety disorder comorbidity negatively impacts almost all aspects of the presentation and course of BD and makes for a much poorer treatment-response and outcome. Though research data on aetiology and management of such comorbidity is limited, clinicians need to screen patients with BD for anxiety disorders and provide comprehensive and on-going treatment to prevent the deleterious consequences of anxiety disorder comorbidity in BD.