Development, cross-cultural adaptation process and preliminary validation of the Italian version of the Nepean Dysphoria Scale

Objectives Dysphoria is a complex emotional state that is prevalent in the clinical setting but very vague in its precise meaning. The aim of this study was to develop and validate the Italian version of the Nepean Dysphoria Scale (NDS-I), a self-report questionnaire developed to measure the severity of dysphoria. Methods The NDS was translated into Italian and subjected to a cross-cultural adaptation process according to standard guidelines. The scale was then administered to 132 psychology students, together with other conceptually similar (Beck Depression Inventory II, Dysfunctional Attitude Scale - Form A, Toronto Alexithymia Scale) and conceptually different (Anxiety Sensitivity Index - 3) instruments. Results The NDS-I demonstrated excellent internal consistency (Cronbach alpha = 0.949). Factor analysis confirmed four factors related to irritability, discontent, interpersonal resentment and surrender. There were medium to strong correlations between the scores on the NDS-I and its subscales and the scores on the Beck Depression Inventory II, and weak to medium but still significant correlations with the scores on the other instruments. Conclusions The NDS-I has good psychometric properties, thus supporting the validity of the original scale. Further research in clinical samples is needed to test it as a tool for routine clinical practice.