BackgroundSince February 14, 2022, Ukraine has once again been under attack by the Russian forces, putting the nation in one of the biggest emergencies in Europe since World War II. This puts Ukrainians at high risk of psychiatric disorders, amidst unseen attacks on infrastructure that have put massive strain on Ukraine’s mental health services. Despite this, the prevalence of psychiatric disorders among adolescents and their changes over time have not yet been documented in Ukraine during the invasion. More generally, there is a need to more comprehensively uncover the long-term consequences of war on youth, especially their risks and protective factors.MethodsThe Adolescents of Ukraine During the Russian Invasion (AUDRI) Cohort is the largest cohort of war-affected Ukrainian adolescents. We will recruit adolescents aged 15 to 18 years attending any school in Ukraine. Data collection will start early 2023, and will be held via online questionnaires every six months during the war as well as after the war has terminated. We will use several well-validated tools to screen for PTSD, depression, anxiety, substance use disorder, and eating disorders. In addition, we will ask participants about possible risks and protective factors of their mental health including resilience and social capital. Using the cohort, we will evaluate the trends in psychiatric disorder prevalence among adolescents in Ukraine over time and evaluate risks and protective factors of adolescents’ mental health.DiscussionThe AUDRI Cohort will provide a unique opportunity to learn more about trauma and resilience among youth in conflict settings, in addition to aiding international efforts to save the mental health of youth in Ukraine. At-risk adolescents identified from our study can directly become beneficiaries of targeted intervention themselves. Building evidence on the mental health of adolescents is especially valuable, as protecting the mental health of war-affected adolescents could help rebuild society and have positive consequences for generations to come.