Background: Misdiagnosis is common in bipolar disorder (BD). Currently used screening tools are brief and cost-effective, but there is a lack of understanding of their reliability over time as well as whether responses are influenced by demographic or clinical factors. Aims: To examine the cross-sectional and longitudinal reliability and validity of two commonly used screening tools as well as their associations with current mood states and other participant characteristics. Methods: 331 adult patients with a diagnosis of BD completed the Mood Disorder Questionnaire (MDQ) and the Hypomania Symptom Checklist-32 (HCL-32) as well as measures of mood online at baseline and three months later. Results: The MDQ was found to have low reliability with poor internal consistency (α= 0.531; α= 0.647 at respective timepoints) and test-retest reliability (rs=0.582). The HCL-32 was more reliable with good internal consistency (α= 0.815 at both timepoints) and test-retest reliability (rs=0.725). MDQ scores were significantly, positively associated with comorbidities and current symptoms of activation/mania, and negatively correlated with age and years since last hospitalisation. The HCL-32 was also significantly positively correlated with activation/mania, and negatively correlated with age, years since diagnosis and years since last hospitalisation. BD-I patients scored higher than other BD-subtypes. Mood state was the only variable with a significant change over time. Conclusions: The HCL-32 appeared more reliable than the MDQ, although all participants needed to exceed an MDQ threshold at baseline to participate in the study, which may have biased our results.
Tröger et al. (Sat,) studied this question.