Validation and optimal cut-off score of the World Health Organization Well-being Index (WHO-5) as a screening tool for depression among patients with schizophrenia.

Background: The utility of the World Health Organization Wellbeing Index (WHO-5) as rapid screening tool for depression has not yet been researched in the context of schizophrenia. The goals of this study were twofold: (1) to test the psychometric properties of the WHO-5 in a sample of Arabic-speaking patients with schizophrenia from Lebanon, with particular emphasis on validating the WHO-5 as a screening tool for wellbeing and depression in patients with schizophrenia; and (2) to determine the optimal cut-off point to identify schizophrenia patients with depression.

Methods: Chronic, remitted patients with schizophrenia took part in this cross-sectional study between August and October 2023 (n = 117; mean age of 57.86 ± 10.88 years and 63.3% males). The Calgary Depression Scale for Schizophrenia (CDSS) was included as index of validity. For the validation of the WHO-5 scale, we performed a confirmatory factor analysis (CFA) using the original structure of the scale. To assess the discriminatory validity of the Arabic version of the WHO-5 as a screening tool for depression, we conducted a Receiver operating characteristic (ROC) curve analysis, taking the WHO-5 reversed score against the dichotomized CDSS score at a cut off value of 6.

Results: The results of CFA supported the originally proposed unidimensional structure of the measure, with good internal consistency reliability (α = 0.80), concurrent validity, and cross-sex measurement invariance. The WHO-5 showed a sensitivity of 0.8 and a specificity of 0.7 in the detection of depression with a cut-off point of 9.5. The validity of the WHO-5 as a screening tool for depression was supported by the excellent discrimination AUC value of 0.838. Based on this WHO-5 cut-off value, 42.6% of the patients were screened as having a depression.

Conclusion: The study contributes to the field by showing that the WHO-5 is a concise and convenient self-report measure for quickly screening and monitoring depressive symptoms in patients with schizophrenia. It is therefore highly recommended to apply this cut-off point for screening and follow-up assessments. The current findings will hopefully encourage clinicians and researchers working in Arab settings, who are often confronted with significant time and resource constraints, to start using the WHO-5 to aid their efforts in mitigating depression in this vulnerable population and fostering research in this under-researched area.