Current mental health service provision for young people was primarily designed based on an assumption of repeat attendance to enable access to interventions. This applies to in-person therapy and, in recent years, digitally provided apps and programmes. Yet, discontinuation after only one or two attendances or uses is a common problem. However, there is a different model, which is intentionally designing provision without assuming repeat attendance, that is, single session interventions. Evidence from the United States, where a suite of digital, self-help single session interventions, accessible anonymously, have been designed, indicates that these are helpful to young people with reductions in depression symptoms at up to 9 months later. These interventions also have had better reach into currently underserved populations (e.g. LGBTQ+ and ethnic minority adolescents). Therefore, these may be a potentially helpful way to expand existing provision at scale, enabling all young people to access evidence-based help quickly.