Validation and psychometric evaluation of a brief screening questionnaire for psychological distress in patients with psoriasis

Background Patients with psoriasis are at risk of a co-morbid diagnosis of depression and/or anxiety. It is therefore essential for dermatologists to have valid and effective instruments that can screen and monitor depression and anxiety symptoms in psoriasis patients. Objective The aim of this study was to validate the Mental Health Inventory (MHI-5) as a brief measure that can be used to evaluate psychological distress related to anxiety and depression in psoriasis patients. Methods The sample included 76 adult dermatological outpatients diagnosed with psoriasis. Participants completed the MHI-5, the Hospital Anxiety and Depression Scale (HADS) and six subscales of the Self-Compassion Scale (SCS). Confirmatory factor analysis (CFA) was applied to examine the factor structure of MHI-5. Convergent validity was examined by applying correlations among all measures. Discriminant validity was examined by applying hierarchical regression models. Reliability was examined by calculating Cronbach's alpha coefficient. Results Confirmatory factor analysis showed that the proposed one-factor model has a good fit to the data. The MHI-5 demonstrated satisfactory convergent validity by yielding significant moderate to strong correlations with the HADS and with the positive and negative subscales of the SCS. Discriminant validity was also evident with being at risk of anxiety predicting MHI-5 scores above and beyond the effect of gender and age. Hierarchical regressions were not performed because a very small number of participants (n = 3) were classified at risk of depression. The MHI-5 showed high internal consistency (alpha = 0.84). Conclusion This investigation provided evidence that MHI-5 is a reliable and valid instrument that can be used to effectively capture psychological distress in psoriasis patients.