Cost-effectiveness of digital health interventions for supporting mental health of children and young people: a rapid review and narrative synthesis.

Globally in 2021, about 1 in 4 children and young people (CYP) below age 25 lived with poor mental health. Various forms of digital health interventions (DHIs) have been introduced in attempts to address unmet mental healthcare needs among young people. DHIs use websites or applications in computers, tablets, or smartphones to deliver mental health interventions, which are either self-directed, or therapist guided. This rapid review synthesises the evidence on the cost-effectiveness of DHIs for supporting mental health in CYP. A literature search was carried out in MEDLINE and PsycINFO using Ovid platform. The search was restricted to peer-reviewed studies published in English between Jan 2018 to May 2025. Eligible studies were identified using the population, intervention, comparator, outcome, and study design (PICOS) framework. Studies were eligible for inclusion if they provided a trial- or model-based full economic evaluation or return on investment of a DHI targeting mental health in CYP up to 25 years of age. Titles and abstracts of 1,265 records were screened. 15 studies met the criteria for inclusion following full-text screening of 28 studies. The focal outcomes in the studies included reduction in symptoms linked to depression, anxiety, and alcohol use. Most studies evaluated computerised cognitive behaviour therapy (CBT) or interventions that included aspects of CBT as the primary intervention. All studies except two reported the DHIs to be cost-effective, at least under certain conditions. Two model-based and three trial-based studies reported that the interventions were dominant (cost saving and more effective) with respect to at least one outcome measure. There is some evidence to suggest DHIs hold the potential to expand and extend mental health support for CYP with minimal therapist involvement. Yet, the evidence is not conclusive due to short follow-up periods, variability in the methodological approaches and reporting of results. High quality evidence on cost-effectiveness of DHIs with comparable methodological approaches is needed to inform implementation decisions.