Building a strong connection to a social group helps clinically depressed patients recover and helps prevent relapse, according to a new study. While past research has looked at the importance of social connections for preventing and treating depression, it has tended to emphasize interpersonal relationships rather than the importance of a sense of group identity. In addition, researchers haven't really understood why group therapy works. "Our work shows that the 'group' aspect of social interaction is critical," the authors note.