Use of the 33-Item Hypomania Checklist (HCL-33) to Distinguish Bipolar Disorder From Major Depressive Disorder in Older Adults.

BACKGROUND

Bipolar disorder (BD) is often misdiagnosed as major depressive disorder (MDD) in older patients. This study examined the psychometric properties of the 33-item Hypomania Checklist (HCL-33) and its accuracy to differentiate BD from MDD among older adults.

METHOD: A total of 215 depressed older patients were recruited; 107 were diagnosed with BD (71 with BD-type I and 36 with BD-type II) and 108 with MDD. Principal components analysis (PCA) was used to explore the factor structure of the HCL-33. Cronbach's alpha was calculated to test the internal consistency. Intra-class correlation coefficient (ICC) was used to measure test-retest reliability. The receiver operating characteristic (ROC) analysis was used to generate the optimal cut-off value to differentiate between BD and MDD.

RESULTS

Two factors were identified in the PCA analysis accounting for 33.9% of the total variance. The Cronbach's alpha value for the HCL-33 was 0.912, with 0.922 for factor I and 0.664 for factor II. The test-retest reliability was excellent (ICC: 0.891). The optimal cut-off of the HCL-33 total score for discriminating between MDD and BD was 14, with a sensitivity of 88.8% and specificity of 82.4%.

CONCLUSION

The HCL-33 had satisfactory reliability and validity and could be used to distinguish BD from MDD in older adults.