Comorbid anxiety in bipolar spectrum disorders: A neglected research and treatment issue?

Abstract Background Anxiety disorders are highly prevalent among patients with bipolar disorder and have a substantial impact on the course of illness and response to treatment. Despite the substantial impact that comorbid anxiety disorders have on the prognosis of individuals with bipolar disorder, many aspects of this comorbidity have received little attention from researchers. This study aims to document the current state of the literature on the comorbidity between anxiety and bipolar disorders by analyzing publication trends on the subject. Method This study is a quantitative and qualitative review of articles on the comorbidity between anxiety disorders and bipolar disorder published between 1990 and 2010 in the ISI Web of Science, Medline and PsycINFO databases. The number of articles published each year on this comorbidity was calculated and compared to the literature published on bipolar disorder as a whole. Articles were classified into five categories and 13 subcategories to identify the main focuses of the literature and current gaps in the knowledge on the subject. Results Interest in the comorbidity between anxiety disorders and bipolar disorder grew continually since 1990, but seems to have reached a plateau. The majority of articles addressing this comorbidity are descriptive in nature, with very few concrete studies examining the mechanisms and treatment approaches that might lead to positive advancements in the field. Limitations Articles written in languages other than English or French were not reviewed. Conclusions It is time to step up research efforts to better understand and manage this under-studied combination of disorders.