Digital Isolation and Depression Risk in Older Adults: An 8-Year Longitudinal Study Using the NHATS Database (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 likelihood of developing mental health disorders, with depression being a primary concern. Although digital isolation has been studied less frequently than traditional social isolation, it may be a significant contributor to both the initiation and progression of depression in this population. OBJECTIVE This investigation seeks to assess longitudinal relationships between multidimensional digital disengagement (encompassing four dimensions: mobile device utilization, computer interaction, electronic correspondence, and web-based engagement) and incident depression among older adults, utilizing longitudinal data from the nationally representative National Health and Aging Trends Study (NHATS). METHODS The analysis was conducted based on the NHATS dataset, a nationally representative longitudinal survey employing multistage sampling to represent community-dwelling Medicare beneficiaries aged 65 and older in the US. We analyzed data from 2011 (Round 1) to 2018 (Round 8), including 8,199 participants in the discovery and validation cohorts. Digital isolation was measured using self-reported data on smart phones, computers, email, and internet platforms, with each categorized as isolated (1) or not isolated (0). Weighted Cox regression models with proportional hazards assumptions were employed to quantify longitudinal associations between digital disengagement and incident depression, incorporating multivariable adjustment for sociodemographic characteristics (age, sex, race or ethnicity), socioeconomic indicators (education level, family income, marital status), and clinical profiles (tobacco use history, multimorbidity burden). Time-to-event analyses were visualized through Kaplan-Meier estimators, complemented by prespecified subgroup analyses evaluating effect modification patterns through interaction term testing. RESULTS Integrated analysis of combined cohorts demonstrated a robust longitudinal association between digital disengagement levels and depression incidence (crude model: HR=1.75, 95%CI 1.60-1.92; fully adjusted model: HR=1.35, 95%CI 1.18-1.55; both P<0.001). Participants exhibiting elevated disengagement showed 1.75-fold greater hazard of developing depression compared to those with minimal disengagement, demonstrating a dose-response gradient that persisted after comprehensive covariate adjustment. 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 The study reveals a robust correlation between increased digital isolation and a higher likelihood of depression in the elderly population. These results underscore the importance of implementing tailored public health strategies to address digital isolation, especially for older adults. To minimize its detrimental effects on mental health, policy makers should encourage digital literacy programs and strengthen mental health services.