The Prevalence of Bipolar Disorder in Primary Care Patients With Depression or Other Psychiatric Complaints: A Systematic Review

BackgroundBipolar disorder prevalence in primary care patients with depression or other psychiatric complaints has been measured in several studies but has not been systematically reviewed.ObjectiveTo systematically review studies measuring bipolar disorder prevalence in primary care patients with depression or other psychiatric complaints.MethodsWe conducted a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method in January 2013. We searched 7 databases using a comprehensive list of search terms. Included articles had a sample size of 200 patients or more and assessed bipolar disorder using a structured clinical interview or bipolar screening questionnaire in adult primary care patients with a prior diagnosis of depression or had an alternate psychiatric complaint.ResultsOur search yielded 5595 unique records. Seven cross-sectional studies met our inclusion criteria. The percentage of primary care patients with bipolar disorder was measured in 4 studies of patients with depression, 1 study of patients with trauma exposure, 1 study of patients with any psychiatric complaint, and 1 study of patients with medically unexplained symptoms. The percentage of patients with bipolar disorder ranged from 3.4%–9% in studies using structured clinical interviews and from 20.9%–30.8% in studies using screening measures.ConclusionsBipolar disorder likely occurs in 3%–9% of primary care patients with depression, a trauma exposure, medically unexplained symptoms, or a psychiatric complaint. Screening measures used for bipolar disorder detection overestimate the occurrence of bipolar disorder in primary care owing to false positives.