Transcultural validity of the Hypomania Checklist-32 (HCL-32) in patients with major depressive episodes

Objectives: There is mounting evidence that current diagnostic systems inadequately recognize clinically relevant levels of hypomania in depressed patients, thereby leading to an under-diagnosis of bipolar disorders and the associated risk of treatment that is inappropriate or may actually worsen illness course. The Hypomania Checklist-32 revised version 2 (HCL-32-R2) is a self-rating scale for hypomanic symptoms specifically developed to address this problem. The goal of this study was to assess the transcultural validity of the HCL-32-R2. Methods: Measurement invariance of HCL-32-R2 responses from the multinational Bipolar Disorders: Improving Diagnosis, Guidance, and Education (BRIDGE) Study of 5635 patients with major depressive episodes (MDEs) was assessed by exploratory and confirmatory factor analysis across five cultural regions. Results: Two previously identified factors were reproduced and explained 60% of the variance in test responses. Only three out of 32 items had cross-culturally variable factor loadings. Some moderate measurement invariance was also found with regard to age and gender. In discriminating unipolar from bipolar disorder, the HCL-32-R2 showed a sensitivity of 82% with a specificity of 57% when current DMS-IV criteria for bipolar disorder were used, and substantially higher specificity of 73% when evidence-based modified criteria were applied. Conclusions: The psychometric properties of the HCL-32-R2 were largely culture-independent. This finding replicates that of our previous international study and is a step towards validating the HCL-32-R2 as a broadly applicable screening instrument for hypomanic features, facilitating the detection of hidden bipolarity in depressed patients.