Abstract
Single-item measures (SIMs) are increasingly used by digital mental health services for assessment, outcome monitoring, and population-level surveillance. Their simplicity offers clear advantages, including good face validity, practical efficiency, and the potential to integrate across digital platforms. However, concerns persist regarding their reliability and suitability for complex psychological constructs. This mini narrative review synthesises recent literature examining the use of SIMs in mental healthcare over the past decade. A total of 31 articles underwent full-text review, and key themes were identified. Findings suggest that SIMs demonstrate acceptable validity for narrowly defined constructs and are valuable for large-scale screening and digital integration, though systematic validation across diverse populations is essential. These results suggest that SIMs should not replace comprehensive assessments, but they can complement integrated, person-centred models of measurement in digital mental healthcare.