The Relationship Between Social Isolation and Depression in Older Adults: The Mediating Role of Activities of Daily Living

Background: With the growing older adult population, increasing attention has been directed toward the determinants of their mental health. Depression is one of the most prevalent psychological disorders in later life, and identifying the factors associated with its development is essential for prevention, early detection, and the promotion of mental health among older adults. Therefore, the present study was conducted to examine the mediating role of activities of daily living (ADLs) in the relationship between social isolation and depression among older adults.
Method: This correlational study employed path analysis. The study population consisted of older adults residing in nursing homes in Ilam city in 2025. A total of 180 participants (72 men and 108 women, aged 65 to 90 years) were selected using a convenience sampling method. Data collection instruments included the Geriatric Depression Scale, the Lubben Social Network Scale, and the Mahoney and Barthel ADLs Questionnaire. Data were analyzed using Pearson’s correlation coefficient and path analysis through SPSS and AMOS version 27.
Results:  The findings indicated that social isolation was associated with lower levels of daily functioning and higher levels of depression. ADLs showed a significant negative relationship with depression. Furthermore, the results of the path analysis indicated that the indirect association between social isolation and depression through ADLs was also significant (β = 0.21, p < .05).
Conclusion: These results suggest that enhancing older adult’s ability to perform ADLs may alleviate the adverse effects of social isolation on depression and contribute to the maintenance of their mental health.
EXTENDED ABSTRACT
Introduction
The rapid growth of the older adult population is accompanied by a range of psychological health problems, including depression. Depression causes clinically significant distress and impairment in individuals’ daily lives and affects social, family, and occupational functioning. Previous studies have confirmed the association between depression and several variables, including social isolation. Various factors, such as physical health problems, loss of loved ones, and reduced social interactions, may contribute to the experience of social isolation among older adults. Although the relationship between social isolation and depression has been confirmed in numerous studies, the precise mechanism and pathway through which social isolation is associated with depression in older adults remain insufficiently understood. In this process, activities of daily living (ADLs) may represent another potentially influential variable.
Evidence suggests that ADLs are associated with both social isolation and depression. However, no study has examined the underlying mechanism linking social isolation and depression or the mediating role of ADLs among older adults in Iran. Therefore, considering this gap in the research literature, the present study aimed to investigate the relationship between social isolation and depression through the mediating role of ADLs in older adults.
Method
The present study used a correlational design based on path analysis. The statistical population consisted of all older adults aged 65 years and above residing in nursing homes in Ilam, Iran, in 2025–2026. From this population, 200 participants, including 85 men and 115 women, were selected through convenience sampling. The inclusion criteria were: (1) being 65 years of age or older, (2) having the ability to read and write, and (3) residing in nursing homes. Eligible participants completed the Yesavage Geriatric Depression Scale, the Lubben Social Network Scale, and the Mahoney and Barthel ADLs Questionnaire. Before administering the instruments, the objectives, significance, and nature of the study were fully explained to the participants, and written informed consent was obtained from them. The criteria for exclusion from the analysis included withdrawal from participation, severe physical or psychological problems affecting the validity of responses, and incomplete completion of the research questionnaires. Of the 200 completed questionnaires, 20 incomplete questionnaires were excluded, and the data from 180 valid questionnaires were analyzed as the final study sample. Finally, the data obtained from the questionnaires were analyzed using Pearson correlation coefficients and path analysis in SPSS version 27 and Amos version 27.
Results
Before conducting the main analyses, it was confirmed that all research variables had a normal distribution. The results also indicated that the assumptions of independence of errors and absence of multicollinearity were met. To test the research hypotheses, the path coefficients among the study variables were examined. Accordingly, path analysis was used to evaluate the path coefficients. The results of Pearson correlation analysis showed a significant positive correlation between social isolation and depression, a negative correlation between social isolation and ADLs, and a negative correlation between ADLs and depression.
The results of path analysis indicated that all direct relationships among the variables in the model were significant. In addition, the percentile bootstrap method with 5,000 resamples and a 95% confidence interval was used to estimate and test the significance of the indirect paths. The results showed that the lower and upper bounds of the confidence interval for ADLs as a mediator between social isolation and depression were 0.263 and 0.379, respectively, with statistical significance at p<.05. Therefore, the indirect relationship was significant, indicating that ADLs play a mediating role in the relationship between social isolation and depression.
Conclusion
In later life, factors such as reduced physical abilities, the onset of multiple illnesses, retirement, and loss of occupational roles may lead to decreased interpersonal interactions and restricted support networks. Such conditions can contribute to the development of social isolation, which, through reduced social relationships, may decrease quality of life and intensify depressive symptoms among older adults. In addition, age-related changes may reduce an individual’s ability to independently perform ADLs. Increased dependence on others may, in turn, create feelings of being a burden, reduce self-efficacy, and ultimately contribute to greater social isolation. Furthermore, limitations in performing ADLs and the continuous need for assistance from others may reinforce feelings of guilt, lower self-esteem, and perceptions of uselessness, all of which are among the well-known antecedents of depression. Ultimately, older adults with lower levels of independence in daily activities may be less able to engage in social activities comparable to those of their peers, which can negatively affect their mental health. Conversely, older adults with greater ability to perform daily activities may use this capacity as a mechanism for reducing depression through social participation, physical activity, or other strategies that promote mental health.
Ethical Consideration
Ethical Code
Ethics approval: The present article was conducted independently after obtaining approval from the 180th meeting of the Research Council of Islamic Azad University, Ilam Branch, dated January 7, 2026.
Funding
This study received no financial support.
 
Authors’ Contributions
A.V: Conceptualization, methodology, software, validation, formal analysis, investigation, data curation, writing – original draft, writing – review & editing, project administration, supervision, and visualization
Conflict of Interest
 The authors declared no conflicts of interest.
Acknowledgments
The author would like to express sincere gratitude to all those who assisted in conducting this study, especially the respected older adults who participated in the research, as well as the planners of Islamic Azad University, Ilam Branch, who provided the opportunity to carry out this study.
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