Italian validation of the Orbach and Mikulincer Mental Pain Scale-8 (OMMP-8)

Background: Mental pain is increasingly recognized in clinical settings as a significant transdiagnostic construct that can exacerbate the condition of individuals suffering from it. It is also widely acknowledged as one of the strongest indicators of suicide risk. This study focuses on the Italian validation of the Orbach and Mikulincer Mental Pain Scale-8 (OMMP-8). Methods: A total of 1,546 participants responded to an online cross-sectional survey assessing sociodemographic and clinically relevant variables, mental pain and other mental health variables (i.e., tolerance for mental pain, current physical pain, anxiety and depression, and wellbeing). Results: The Italian version of the OMMP-8 maintained the same factorial structure as the original instrument and demonstrated excellent convergent validity. Moreover, the instrument showed strong criterion validity, effectively distinguishing between individuals receiving mental health treatment, those with recent suicidal ideation, and those with a history of suicide attempts. ROC curve analyses indicated good discrimination for recent suicidal ideation (AUC = 0.81) and acceptable discrimination for suicide attempt history (AUC = 0.71), with an optimal cut-off score of ≥ 21.5. In addition, the Italian OMMP-8 demonstrated incremental validity, predicting suicidal ideation and past suicide attempts after controlling for depressive symptoms. It also exhibited scale measurement invariance for gender, age, current mental health treatment, and current suicidal ideation while residual invariance was established for gender, age, and treatment status. Conclusion: The Italian OMMP-8 is an agile, valid, and reliable instrument for assessing mental pain and shows promise in identifying individuals at risk of suicide.