This Special Issue deals with the topic of how people and social groups face problems in an increasingly complex and globalized society. The topics included in the call for papers were the interaction of psychosocial well-being and mental health with economic, gender, racial and ethnic inequalities, migration and demographic change and conflict and war, as well as the effects of stigma on people discriminated against because of their differential characteristics, whether they are of a sexual, disability or other minority. We made this proposal because we believed that, despite the introduction of the biopsychosocial model in the late 1970s as a paradigm of the integration of different disciplinary views, research in mental health and psychosocial well-being is still highly fragmented. For decades, we have tried to advance by emphasizing a part of the equation, with results that are at least modest. Therefore, in this Special Issue, we prioritized works aiming at disciplinary and methodological integration. The Special Issue was open to any subject area related to the impacts of social issues on mental health and psychosocial well-being. We were interested in empirical and theoretical enquiries at all ecological levels, from the psychosocial impact of social dynamics on individuals, to the analysis of how sociocultural and geopolitical factors influence health and collective psychosocial well-being.