Mental health and disorders. Editorial.

Mental health and mental disorders pose a tremendous challenge to the societal, health, and research policies in Europe, and sound advice is needed on a potential strategy for mental health research investment. Toward this goal, the ROAMER initiative ("Roadmap for Mental Health Research in Europe") was launched to map the current state of the art, to identify gaps and to delineate advances needed in various areas and domains of mental health research in Europe. To further stimulate discussions among the scientific community and stakeholders on how to improve mental health research and to promote an improved research agenda for the next decade, this IJMPR topic issue presents the overall ROAMER methodology as well as a series of selected papers highlighting critical issues of psychological approaches and interventions as outcomes of the ROAMER work package 5 "Psychological research and treatments".