Measuring depression with a well-being index: Further evidence for the validity of the WHO Well-Being Index (WHO-5) as a measure of the severity of depression

BackgroundIn recent years, the WHO Wellbeing Index (WHO-5) has been used as a screening measure for depression. Nevertheless, research on the validity of this measure in the context of clinical depression is sparse.QuestionsThe aim of the present study was to investigate the measurement invariance of the WHO-5 across depressed and non-depressed individuals, as well as the shape and specificity of its relationship to measures of depression severity.MethodOf the 414 subjects who completed the WHO-5 and the Beck Depression Inventory-II (BDI-II), 207 had a diagnosis of a major depressive episode (MDE). A subsample also completed the Beck Anxiety Inventory (BAI) and was assessed by clinicians using the Hamilton Depression Rating Scale (HAM-D) and the Hamilton Anxiety Rating Scale (HAM-A).ResultsThe WHO-5 demonstrated strong measurement invariance regarding the presence or absence of a current MDE. The WHO-5 showed a very high negative association with self- and observer-rated measures of depressive symptoms, especially in the range of mild to moderate symptoms. These associations were still substantial after controlling for measures of anxiety symptoms.LimitationsIn addition to a diagnostic interview, only one measure for self- and observer-rated symptoms of depression was used. Furthermore, the observer-rated measure was only assessed in one subsample that exhibited a somewhat restricted range of depression severity.ConclusionAlthough this index was originally designed as a measure of well-being, the results support the use of the WHO-5 in the context of depression research.