One Single Session to Sleep Them All? The Potential of Single-Session Interventions for Insomnia.

Poor sleep and insomnia are pervasive public health concerns, with insomnia ranking as the second most prevalent mental health disorder in the general population. Moreover, insomnia is a significant predictor of subsequent depression and is frequently co-occurring with other psychological difficulties. While both in-person and digital cognitive-behavioural treatments have proven effective as first-line strategies for managing insomnia, their accessibility remains limited, with several barriers preventing dissemination, particularly, among at-risk or hard-to-reach populations such as adolescents, university students and minority groups. Single-session interventions (SSIs) for mental health have recently emerged as a strategic asset and treatment approach, grounded in specific theoretical tenets and assumptions. The efficacy and feasibility of SSIs have been well documented, with systematic evidence highlighting their flexibility, applicability and cost-effectiveness across a wide range of clinical and subclinical conditions. However, their full implementation in the treatment of insomnia remains limited. This brief review aims to illustrate the alignment between the SSI framework and the needs of psychological treatments for insomnia and to summarise current evidence on single-session, one-shot interventions for insomnia. Notably, several one-shot interventions based on cognitive-behavioural therapy for insomnia have been tested in clinical trials with promising results, though their integration with the broader SSI approach appears partial. Further research is warranted to develop consensus-based in-person and digital SSIs for insomnia and to assess their feasibility and effectiveness within a stepped-care framework.