A Longitudinal Cohort Study from the National Health and Aging Trends Study (NHATS) (Preprint)

BACKGROUND The rapid advancement of digital technologies has profoundly transformed communication practices. However, this technological revolution has also led to "digital isolation," a form of social disconnection caused by limited or absent engagement with digital communication tools, including smartphones, computers, email, and the internet. This issue is particularly concerning for older adults, as it may increase their risk of mental health disorders, particularly depression. Although digital isolation has been studied less frequently than traditional social isolation, it may play a crucial role in the onset and progression of depression in this population. OBJECTIVE This study aims to examine the association between various forms of digital isolation (mobile phone use, computer use, email communication, and internet activity) and depression risk in older adults, using data from a large longitudinal cohort. METHODS We used data from the National Health and Aging Trends Study (NHATS), a nationally representative cohort of adults aged 65 and older. We analyzed data from 2011 (Round 1) to 2018 (Round 8), including 8,199 participants in the discovery and validation cohorts. Digital isolation was assessed based on self-reported use of mobile phones, computers, email, and internet platforms, with each categorized as isolated (1) or not isolated (0). We applied Cox proportional hazards regression models to examine the relationship between digital isolation and depression risk, adjusting for key confounders, including age, gender, race/ethnicity, education, income, marital status, smoking, and chronic disease burden. Kaplan-Meier survival curves and stratified analyses were conducted to further explore these associations across subgroups. RESULTS Pooled sample analysis indicated a significant association between digital isolation and depression risk. Participants with high digital isolation had a significantly increased risk of depression compared to those with low digital isolation. The unadjusted hazard ratio (HR) for high digital isolation was 1.75 (95% CI: 1.60–1.92, P < 0.001), while the adjusted HR was 1.35 (95% CI: 1.18–1.55, P < 0.001). Specific aspects of digital isolation, including computer, email, and internet use, were significantly linked to depression risk, whereas mobile phone isolation had a weaker association. CONCLUSIONS This study provides strong evidence that greater digital isolation is significantly associated with a higher risk of depression in older adults. These findings highlight the need for targeted public health interventions to mitigate digital isolation, particularly among older adults. Public health policies should promote digital literacy initiatives and enhance mental health support to reduce the negative impact of digital isolation on mental well-being. CLINICALTRIAL digital isolation; depression; older adults; longitudinal cohort study; NHATS; mental health; social isolation; technology use; risk factors; public health interventions