Cross-cultural sensitivity of the euthymia scale

Background: In recent years, there has been a reappraisal of the concept of euthymia as a transdiagnostic construct where lack of psychiatric disorders is associated with the presence of positive affect, psychological well-being and flexibility, a subjective sense of consistency, and resistance to stress. Using clinimetric principles, a self-rated instrument, the euthymia scale (ES), was developed to assess the main components of euthymia. The aim of this study is to evaluate the clinimetric sensivity of the Italian, Chinese, and Japanese versions of the ES testing their applicability across different cultures. Methods: A convenience sample of 951 participants was used for assessing the clinimetric sensitivity of the Italian version of the ES. As to the Chinese sample, it included a total of 295 inpatients recruited from different medical settings, while the Japanese one consisted of 1030 individuals who completed an online survey. Results: As to the Italian version of the ES, a Person Separation Reliability Index of 0.88 was found. Mann-Whitney test comparisons showed that patients without depression scored significantly higher on the Chinese version of the ES than those with depression. The analysis of variance revealed that the Japanese version of the ES discriminated between healthy controls and those with current major depression, and sensitively differentiated healthy individuals from participants with a history of major depression and moderate to severe symptoms of psychological distress. Conclusion: The findings of the present study indicate that the ES is a highly sensitive clinimetric index that can be used as a cross-cultural screening measure.