Introduction: Depressive episodes/symptoms of bipolar I disorder (BPD‐I) are commonly misdiagnosed as major depressive disorder (MDD). We developed a brief, self‐rated, pragmatic tool that screens for manic symptoms and identifies BPD‐I risk factors (eg, age of onset) to reduce misdiagnosis of BPD‐I as MDD.
Method: Existing questionnaires and risk factors were identified through a targeted literature search to select concepts thought to differentiate BPD‐I from MDD. Individuals with self‐reported BPD‐I or MDD (N = 12) participated in cognitive debriefing interviews to test and refine item wording. An observational study was conducted to evaluate the tool's predictive validity. Participants with clinical interview‐confirmed diagnoses of BPD‐I or MDD completed a 10‐item screening tool and other questionnaires. Data were analyzed to identify a smaller subset of items with optimized sensitivity and specificity.
Results: Of 160 interviews conducted, 139 patients had confirmed BPD‐I (n = 67) or MDD (n = 72). The screening tool was reduced from 10 to 6 items based on item‐level analysis. When 4 items or more were endorsed (“yes”), the performance of this tool for identifying patients with BPD‐I was 0.92 and specificity was 0.78; positive and negative predictive values, based on the analysis sample, were 0.78 and 0.92, respectively. These properties represent an improvement over the Mood Disorder Questionnaire, while using >50% fewer items.
Conclusion: This brief and valid screening tool serves to identify patients with depressive symptoms who may have BPD‐I instead of MDD, prompting more comprehensive clinical assessment, improved diagnostic accuracy and treatment selection, and enhanced health outcomes in busy clinical practices.
