Stratifying the Risk of Depression in Adolescence: The IDEA-RS Calculator.

Adolescent depression remains one of the leading causes of disability worldwide, contributing substantially to the global burden of disease.1 Despite growing interest in early identification and prevention of depression, a persistent challenge is to deliver the right support to the right young people, at the right time. Lessons from other fields in medicine illustrate how risk-informed prevention-guided by composite prediction models-can make preventive efforts both proportionate and effective. Depression, in particular, demands a multifaceted, individualized approach to early detection-especially during adolescence, when incidence peaks and prevention opportunities are greatest. Psychiatry, however, has traditionally emphasized discrete factors, thereby constraining our capacity to model the complex interplay of risk and protective factors that underlie vulnerability. Current approaches also often rely on subthreshold depressive symptoms, limiting the ability to identify adolescents most at risk before symptoms emerge. Furthermore, although early predictive models show promise, their performance often fails to generalize beyond development samples.