Validation of the Russian version of the hypomania checklist (HCL-33) for the detection of bipolar disorder in patients with a current diagnosis of recurrent depression

•In Russia bipolar disorder misdiagnosed as depression in 30–40% of patients.•New 33-item hypomania self-report (HCL-33) screens for past hypomanic episodes.•Russian HCL-33 effectively detects bipolar disorder in patients with depression.•Short 6-item version of the HCL proposed with good specificity and sensitivity.•Limitations: specific sample and no comparisons with other self-report instruments. Bipolar disorder (BD), particularly BD-II, is frequently misdiagnosed as recurrent depressive disorder (RDD) because past hypomanic episodes are missed. The self-report Hypomania Checklist-32 (HCL-32) is a sensitive and reliable instrument with validated transcultural stability for detecting a history of hypomanic symptoms. The 33-item Hypomania Checklist (HCL-33) is a slightly modified version of the HCL-32. Alongside the HCL-33 self-report version, a new instrument for external assessment was developed. The objective was validation of the psychometric properties and the accuracy of the Russian version of the HCL-33 to identify BD in patients with a current diagnosis of RDD. The HCL-33 was completed by 150 outpatients and inpatients with a formal diagnosis of RDD in two Moscow state psychiatric settings. International Classification of Disorders (ICD-10) diagnoses were established using the Russian version of the Mini International Neuropsychiatric Interview (MINI). A screening score of 16 on the HCL-33 was the optimal cut-off that maximized sensitivity (0.71) and specificity (0.69) for the BD diagnosis. The highest Area Under the Curve (AUC) value during Receiver Operator Characteristic (ROC) analysis was 0.773 distinguishing between BD and RDD. The Cronbach's alpha was 0.91, indicating good internal consistency. Principal component analysis identified two factors, “active/elated” and “risk-taking/irritable”. The study scope was limited by the specific nature of the sample and the absence of comparison with other BD screening scales including HCL-32. The Russian version of the HCL-33 is a sensitive, accurate and reliable instrument for the screening of BD patients with depression.