The 33-item Hypomania Checklist (HCL-33): A new self-completed screening instrument for bipolar disorder

Abstract

Background

Bipolar disorder (BD) is often misdiagnosed as major depressive disorder (MDD). This study tested the psychometric properties and the accuracy of the Chinese version of the 33-item Hypomania Checklist (HCL-33) to identify BD in Chinese clinical settings.

Methods

A total of 350 depressed patients were consecutively interviewed in a major psychiatric hospital in China. The patients’ socio-demographic and clinical characteristics were recorded using standardized protocol and data collection procedures. The HCL-33 was completed by patients to detect symptoms characteristic of mania and hypomania. DSM-IV diagnoses were established using the Mini International Neuropsychiatric Interview (MINI).

Results

The HCL-33 showed high internal consistency with two-factorial dimensions. The optimal cut-off point on the HCL-33 to differentiate BD from MDD was 15, while cut-off points of 14 and 13 differentiated BD-I and BD-II from MDD, respectively. The maximum sensitivity was 0.62, 0.67 and 0.72 for differentiating BD, BD-I and BD-II from MDD, respectively.

Conclusions

The HCL-33 is a useful tool for screening for BD in Chinese depressed patients. The routine clinical use of the HCL-33 as a screening instrument for BD in Chinese patients is recommended.

Introduction

Bipolar disorder (BD), particularly BD-II, is frequently misdiagnosed as major depressive disorder (MDD) in clinical practice leading to inappropriate treatment (APA, 2002, Hirschfeld et al., 2003), which, in turn, augments the risk for excess mortality and increases the economic burden. A depressive episode is usually the first mood syndrome at the onset of BD, and depressive episodes are more frequent than manic or hypomanic episodes in the course of the disorder (Solomon et al., 2006). In addition, hypomania is often experienced as normal by patients and their families and therefore not spontaneously reported to clinicians (Hirschfeld et al., 2003). Furthermore, clinicians tend not to investigate hypomania if patients present with a depressive episode. All these factors contribute to the failure to diagnose BD, making its early and accurate identification vitally important. In clinical practice recommendations for improving the diagnostic accuracy of BD include establishing a comprehensive history of hypomania/mania, supplemented with the administration of screening tools (Bowden, 2001, Hirschfeld and Vornik, 2004).

Standardized structured diagnostic interviews, such as the Mini International Neuropsychiatric Interview (MINI) and the Structural Clinical Interview for DSM-IV (SCID), are often used in research and even clinical practice, but applying these tools is time-consuming and requires well-trained raters. To overcome these difficulties, several self-report screening instruments have been developed to aid in the detection of BD. Based on DSM-IV diagnostic criteria, the 32-item Hypomania Checklist (HCL-32) is such a tool, which has been validated in many countries (Angst et al., 2005, Vieta et al., 2007). A transcultural analysis of the Bridge Study (Bipolar Disorders: Improving Diagnosis, Guidance and Education), which administered the HCl-32-R2 (an extended version of the HCL-32), showed that the former had good stability across five geographical regions (Iberia, Central Europe, Eastern Europe, North Africa/Near East, Far East including China) (Gamma et al., 2013). Based on those results, the HCL-33, a slightly modified version of the HCL-32 integrating a few additional questions, was produced. In addition to this self-administered version, a new instrument designed for external assessment was developed.

This study set out to examine the psychometric properties and accuracy of the HCL-33 for self-assessment as a screening tool for BD in Chinese depressed patients.