Social relationships play a key role in depression. This is apparent in its etiology, symptomatology, and effective treatment. However, there has been little consensus about the best way to conceptualize the link between depression and social relationships. Furthermore, the extensive social-psychological literature on the nature of social relationships, and in particular, research on social identity, has not been integrated with depression research. This review presents evidence that social connectedness is key to understanding the development and resolution of clinical depression. The social identity approach is then used as a basis for conceptualizing the role of social relationships in depression, operationalized in terms of six central hypotheses. Research relevant to these hypotheses is then reviewed. Finally, we present an agenda for future research to advance theoretical and empirical understanding of the link between social identity and depression, and to translate the insights of this approach into clinical practice.

There is growing recognition that identification with social groups can protect and enhance health and well-being, thereby constituting a kind of "social cure." The present research explores the role of control as a novel mediator of the relationship between shared group identity and well-being. Five studies provide evidence for this process. Group identification predicted significantly greater perceived personal control across 47 countries (Study 1), and in groups that had experienced success and failure (Study 2). The relationship was observed longitudinally (Study 3) and experimentally (Study 4). Manipulated group identification also buffered a loss of personal control (Study 5). Across the studies, perceived personal control mediated social cure effects in political, academic, community, and national groups. The findings reveal that the personal benefits of social groups come not only from their ability to make people feel good, but also from their ability to make people feel capable and in control of their lives.