[Comment] Precision psychology and implementation science: optimising scale

Precision psychology and implementation science: optimising scale-up in mental health Affiliations & Notes aWHO Collaborating Centre for Research and Training in Mental Health and Service Evaluation Department of Neurosciences, Biomedicine and Movement Sciences, Section of Psychiatry, University of Verona, 37135, Verona, Italy bCochrane Global Mental Health, University of Verona, Verona, Italy Article Info Publication History: Published May 13, 2026 DOI: 10.1016/S2214-109X(26)00094-X External LinkAlso available on ScienceDirect External Link Copyright: © 2026 The Author(s). Published by Elsevier Ltd. Linked Articles Download started OkIn The Lancet Global Health, Rita Rosner and colleagues1 report a cluster-randomised controlled trial evaluating a mental health stepped care programme versus enhanced usual care among 627 unaccompanied young refugees originating from 40 countries and resettled in Germany. The sample comprised predominantly male, trauma-exposed adolescents; 43% of participants had elevated post-traumatic stress symptoms (PTSS) at baseline. The stepped care programme, BETTER CARE, comprised screening, a preventive group intervention, and trauma-focused cognitive behavioural therapy; enhanced usual care comprised screening and treatment recommendations only. At 12 months, participants in the BETTER CARE group had a statistically significant reduction in PTSS compared with those in the enhanced usual care group. There were high numbers of dropouts in both groups. This Article provides a valuable stimulus for reflection regarding at least two innovative dimensions. First, the experimental arm of the study was explicitly grounded in a stepped care logic. Rather than applying the same intervention across heterogeneous clinical profiles, the model differentiated between levels of psychological distress. Participants with subclinical distress received a preventive intervention, whereas those meeting the criteria for post-traumatic stress disorder were offered trauma-focused cognitive behavioural therapy. Importantly, this approach facilitates a step away from the one-size-fits-all paradigm that has characterised much of the existing literature on global mental health in recent years2 and aligns with a precision-oriented approach, whereby interventions are matched to individual clinical and sociodemographic profiles. The second innovative dimension concerns the study design. This randomised controlled trial simultaneously considered clinical and implementation outcomes, adopting a type I hybrid effectiveness–implementation design, a crucial methodological advancement in a field in which the majority of trials are designed to test efficacy only. Introducing implementation outcomes recognises the idea of a structured trajectory, from efficacy testing to implementability. Although these advances provide meaningful progress, a coordinated and sustained effort is needed to further advance the field. First, symptom severity alone cannot support a genuine precision paradigm; effective tailoring of psychological interventions requires a broader and more nuanced set of determinants. For example, personal, sociodemographic, and environmental variables should be accounted for alongside clinical factors.3,4 Timing is also important. The analysis of moderators of intervention effects should begin as early as possible, ideally by systematically collecting individual participant data from randomised controlled trials, to identify (and test) which individual-level variables are plausible moderators. The identified moderators could guide allocation of the most appropriate intervention—a strategy to be tested against standard care in a new randomised controlled trial. Second, moving forward, the field should consider shifting from predominantly hybrid type I designs towards hybrid type II and III approaches.5 Although hybrid type I studies prioritise clinical effectiveness, hybrid type II and III designs place stronger emphasis on implementation strategies and real-world integration. Given the persistent gap between evidence generation and routine practice, greater use of hybrid type II and III designs might better accelerate translation, strengthen health system uptake, and ensure that innovations achieve a meaningful population-level impact. Adopting an implementation lens, indicators such as high dropout rates and recruitment duration would not be viewed solely as trial limitations. These are implementation measures that are important for informing adaptation and subsequent scale-up. In the present study, high dropout rates might, therefore, indicate a misalignment between traditional implementation strategies and the structural instability characterising the lives of young refugees globally. Consideration of these measures could lead to adaptations and flexibility in delivery formats, introduction of digital components, transdiagnostic and modular interventions, and the accommodation of legal or living conditions to facilitate continuity of care and consider the different cultural backgrounds of young refugees. All of these adaptations can be studied using hybrid type II and III designs. In addition, this structured pathway from efficacy to implementation would contribute to a clearer and homogeneous definition of implementation outcomes and methodologies in the literature. Finally, these two dimensions have direct implications for scale-up, intended as the culmination of a coherent pathway in which the integration of interventions into the health system is guided by both efficacy and implementation research. Precision psychology supports sustainable scale-up by targeting interventions to those most likely to benefit. Identifying moderators of response could reduce inefficiencies, limit resource waste, and simultaneously strengthen clinical impact and cost-effectiveness. Hybrid implementation research accelerates the shift from efficacy to routine care by generating early evidence on feasibility, acceptability, fidelity, scalability, and system fit. This approach could help address the paradox of high clinical need alongside low engagement and high attrition in migrant populations. The recognition that the principal barriers might no longer lie in the interventions themselves but in delivery systems is key.6,7 Resettlement instability, cultural barriers, stigma, and competing housing, economic, and employment demands all constrain engagement. When reframed as implementation outcomes rather than trial limitations, these factors become crucial evidence to inform subsequent research. This shift in perspective has the potential to reduce the traditional gap in mental health between scientific evidence and clinical practice, mitigating the risk that efficacious interventions fail when integrated into routine care. Competing Interests We declare no competing interests. The authors used ChatGPT-Edu to improve clarity and phrasing in limited sections of the commentary, without generative use. The authors reviewed and edited the text in multiple rounds and take full responsibility for the final published content. References 1. Rosner, R ∙ Pfeffer, E ∙ Thielemann, JFB ∙ et al. Mental health care for unaccompanied young refugees through a stepped care approach versus enhanced usual care: acluster-randomised hybrid effectiveness–implementation trial Lancet Glob Health. 2026; published online May 13 https://doi.org/10.1016/S2214-109X(26)00055-0 2. Purgato, M ∙ Singh, R ∙ Acarturk, C ∙ et al. Moving beyond a ‘one-size-fits-all’ rationale in global mental health: prospects of a precision psychology paradigm Epidemiol Psychiatr Sci. 2021; 30:e63 3. Patel, V ∙ Saxena, S ∙ Lund, C ∙ et al. The Lancet Commission on global mental health and sustainable development Lancet. 2018; 392:1553-1598 4. Lund, C ∙ Brooke-Sumner, C ∙ Baingana, F ∙ et al. Social determinants of mental disorders and the Sustainable Development Goals: a systematic review of reviews Lancet Psychiatry. 2018; 5:357-369 5. Curran, GM ∙ Bauer, M ∙ Mittman, B ∙ et al. Effectiveness–implementation hybrid designs: combining elements of clinical effectiveness and implementation research to enhance public health impact Med Care. 2012; 50:217-226 6. Purgato, M ∙ Muneghina, O ∙ Barbui, C From scaling interventions to tuning systems: rethinking global mental health implementation Int J Soc Psychiatry. 2026; published online Feb 13 https://doi.org/10.1177/00207640261421851 7. Patel, V ∙ Saxena, S ∙ Lund, C ∙ et al. Transforming mental health systems globally: principles and policy recommendations Lancet. 2023; 402:656-666