A bridge too far? Social network structure as a determinant of depression in later life.

Existing research has documented various determinants of mental health related to individuals' social connections, but less is known about the role of the structural features of interpersonal networks. This is especially true in the case of bridging, which refers to ties to people who are otherwise disconnected from each other. By intersecting theories of social networks and gerontology, this study employs within- and between-person analysis with data from the National Social Life, Health, and Aging Project (NSHAP) to examine the association between social network bridging and depression in later life. The study finds that bridging, particularly between kin and non-kin members in the network, is associated with increased depressive symptoms in later life. This association is contingent on social support and strain respondents experienced, and it exhibits variations within individuals over time, especially among older adults in the youngest age cohort (57-64 years old included in NSHAP in 2005). In closing, the paper discusses the extent to which heterogeneous network structures may be one mechanism that shapes mental health trajectories in the context of later life-course experiences.