The WHO-5 Holds Up Across 213 Studies (Topp et al., 2015)

The Question

After nearly two decades and hundreds of studies, does the WHO-5 actually do what the World Health Organization promised in 1998?

What They Found

• The WHO-5 appeared in 213 published studies across more than 30 languages, with consistent evidence supporting its validity in healthy adults, primary-care patients, and clinical populations
• Internal reliability was strong: Cronbach's alpha sat above 0.80 in nearly every sample, comparable to scales five times longer
• For depression screening, the <28 cutoff caught about 86% of true cases and correctly cleared about 89% of healthy people
• The five-item version performed almost as well as longer instruments like the Beck Depression Inventory, despite taking under a minute to complete
• The instrument worked across primary care, psychiatry, geriatrics, oncology, diabetes, and adolescent health, wherever clinicians needed a quick, defensible read of well-being

How They Tested It

• Searched PubMed and PsycINFO for every published study using the WHO-5 since its 1998 release
• Found 213 unique studies; for each, extracted psychometric data on reliability, validity, and responsiveness to change
• Pooled findings across populations (primary care, hospitals, the general public, older adults, students) to test whether performance held up everywhere
• Compared the WHO-5's diagnostic accuracy against established depression scales using the standard sensitivity / specificity framework

Caveats

• A systematic review aggregates existing studies, so it inherits any biases in the published literature, including a general tilt toward studies with positive findings
• Subgroups like adolescents, older adults, and people with chronic illness sometimes need adjusted thresholds rather than the standard <28 cutoff
• Most validation work was done in Western Europe and North America; non-Western language adaptations were thinner at the time of the review