The overarching aim of MentBest is to improve care for patients with depression and to prevent suicidal behaviour in Europe by i) transferring the community-based 4-level intervention concept of the European Alliance Against Depression (EAAD) to new regions and countries in Europe and ii) promoting the uptake of the iFightDepression®-tool, an internet-based self-management tool for patients with depression. Implementation countries (Bulgaria, Estonia, Greece, Italy and Poland) are those countries where EAAD’s 4-level intervention concept has not yet been implemented. In these countries, model regions have been selected in which the 4-level intervention will be implemented and later transferred to other regions. Transfer countries (Hungary, Ireland and Spain) are those countries in which the 4-level intervention concept has already been implemented. These countries will focus on promoting and expanding these interventions to new regions. Both implementation and transfer countries will furthermore promote and coordinate the nationwide implementation of the iFightDepression®-tool and awareness website. MentBest will contribute to reduce the huge diagnostic and therapeutic deficits concerning depression and to prevent suicidal behaviour in Europe, which is particularly timely considering the exacerbation of mental health problems associated with the impacts of Covid-19. Reducing stigma, improving health literacy and help-seeking behaviour are further objectives of MentBest. MentBest will start a long-term process of dissemination of both the 4-level intervention and the iFightDepression®-tool beyond the funding period. Experiences from EAAD member countries have demonstrated that other regions will be encouraged to adopt their own regional 4-level interventions as soon as culturally sensitive materials and support (e.g. by national coordination centre) are available. An explicit goal of Mentbest is to thus ensure long-term sustainability via this self-promoting process.