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The Hypomania Checklist-32 (HCL-32) offers significant value for predicting response to lithium in patients with bipolar disorder, suggests a study published online in the journal Pharmaceuticals.

“Given the variability in lithium response, tools and guidelines that improve the prediction of positive outcomes are invaluable for clinicians and patients,” wrote corresponding author Gabriele Sani, MD, and colleagues.

Clinical predictors of lithium response in patients with bipolar disorder have been studied extensively, researchers reported, but the utility of screening instruments for predicting lithium response has been unclear. This study investigated whether two well-established tools commonly used in bipolar disorder screening could also serve as predictors of lithium response in patients: the HCL-32 and the Mood Disorder Questionnaire (MDQ).

The study included 146 patients with bipolar disorder. Researchers used the Alda Scale to assess lithium response and grouped patients into responder or nonresponder categories. They then examined the differences in HCL-32 and MDQ scores between the groups.

Some 46 (31.5%) patients were categorized as lithium responders, according to the study. Responders scored significantly higher on the HCL-32 compared with nonresponders, although scores on the MDQ did not significantly differ between groups. With the exception of greater use of alternative treatments in nonresponders, sociodemographic and clinical characteristics also did not differ between responders and nonresponders.

In linear regression analysis, HCL-32 scores were a significant direct predictor of lithium response: higher scores on the HCL-32 predicted higher scores on the Alda Scale, researchers reported.

In contrast, gender, age, and MDQ scores showed no association with response.

“The strong association between HCL-32 scores and lithium responsiveness may be attributed to the tool’s sensitivity to manic and hypomanic polarity,” researchers wrote. “These components of bipolar disorder—characterized by impulsivity, overactivity, elevated mood, and increased energy—are effectively captured by the HCL-32, which has demonstrated robust diagnostic sensitivity.”

The MDQ, meanwhile, has a broader scope that is less specific for lithium response but is, nevertheless, valuable for bipolar disorder screening, the authors explained.

“The significant predictive value of the Hypomania Checklist-32 for lithium treatment response could enable more personalized treatment plans,” researchers wrote. “Future studies could expand on these findings, focusing on improving the use of psychometric tools for predicting lithium response, particularly emphasizing the importance of manic polarity in treatment stratification.”