BACKGROUND: Adolescents are at particularly high risk for digital technology overuse, including in response to the COVID pandemic, and are therefore vulnerable for its potential harmful effects on mental health. Problematic usage of the internet (PUI) is thought to represent a marker of disrupted self-management, with major consequences for individual and societal health and wellbeing. AIM: Bootstrap brings together a multidisciplinary consortium aiming to initiate health and social policy and practice change designed to reduce the harmful effects of digitalization on mental health, particularly for young people. APPROACH: We will co-create a digital screening and assessment platform to understand which individuals are at-risk for developing PUI. Algorithm-based models will be used to predict which individual will benefit from which type of self-management intervention, and these preventative behavioral interventions will be tested for their (cost)effectiveness. Finally, we will develop a policy toolkit in co-design with stakeholders, to promote human digital rights accountability at the local, national, and European level. IMPACT: Bootstrap will provide unprecedented scientific knowledge on the psychological mechanisms underlying (risk for) PUI and potential interventions. Improved self-management and tools to optimize healthy internet usage will promote mental health and prevent mental ill health in adolescents, and contribute to reducing stigma. In addition, our policy toolkit will empower policy makers and private companies to (self)regulate with the intent to protect vulnerable groups. In the long run, Bootstrap will thus contribute to improving mental wellbeing across Europe and beyond.