A 5-year longitudinal structural equation model of social isolation and probable major depression among participants with spinal cord injury.

Objective: To develop longitudinal structural models of social isolation and probable major depression (PMD) over a 5-year interval among participants with spinal cord injury (SCI).

Design: Longitudinal structural equation modeling of self-report assessments collected during two follow-ups (2013 as Time 1, 2018 as Time 2) of a 45-year multicohort longitudinal study. Participants (n = 557) were identified from a specialty hospital in the Southeastern United States and two Midwestern hospitals and were initially enrolled in 1973-1974, 1984-1985, 1993-1994, or 2003-2004. PMD symptomology was measured by the Patient Health Questionnaire-9 (PHQ-9) and was defined by PHQ-9 scores ≥ 10. Social isolation was represented by two latent dimensions: social disconnectedness, objective component measured by activities, and perceived isolation, based on subjective appraisals. Structural equation modeling assessed the relationship among social disconnectedness and perceived isolation measured at Time 1 and PMD measured at Times 1 and 2.

Results: Both social disconnectedness and perceived isolation, measured at Time 1, were significantly related with PMD measured at Time 1 (r_{SD_Time 1 and PMD_Time 1} = .49, p < .001; r_{PI_Time 1 and PMD_Time 1} = .66, p < .001) and Time 2 (r_{SD_Time 1 and PMD_Time 2} = .37, p < .001; r_{PI_Time 1 and PMD_Time 2} = .54, p < .001), indicating participants with greater perceived isolation and social disconnectedness were more likely to have greater likelihood of PMD, both cross-sectionally and longitudinally. Perceived isolation was more strongly related to PMD compared with social disconnectedness.

Conclusion: Social isolation was associated with both current and future depression symptoms. People with more years post-SCI were less likely to have PMD. (PsycInfo Database Record (c) 2024 APA, all rights reserved).