Abstract
Maintaining sustainable mental health is an increasing societal challenge in Japan, where psychological distress and sleep problems have become major public health concerns. This study examined how three culturally grounded dimensions of self-construal—Subjective Self (SS), Objective Self (OS), and Autonomous Self (AS)—relate to both positive and negative indicators of psychological adjustment among Japanese adults. This study aimed to examine whether internally guided forms of self-regulation (SS and AS) function as psychological resources, whereas externally guided self-regulation (OS) operates as a potential vulnerability factor in a culturally tight social context. By simultaneously examining multiple indicators of adjustment, this research clarifies how culturally shared self-regulatory patterns are linked to distress and sleep difficulties that affect large segments of the population. From a public health perspective, the findings highlight socially reinforced risk and protective patterns that can inform population-level prevention and mental health promotion in settings such as schools, workplaces, and communities, rather than relying solely on individual clinical intervention. These results underscore the importance of integrating cultural psychology into public health frameworks aimed at promoting sustainable mental health in contemporary and increasingly diverse social environments.