However, the data are often contradictory with respect to the prevalence of the phenomenon: depression may range from about 10-30% in the general population (Alonso and Lepine, 2007).

The gap

Consensus across the literature

Supporting evidence — 8 representative gaps

• Who gains more? subjective socio-economic status in the impact of internet use on older adults’ depression (2026) · doi

  This study makes several meaningful contributions to research on IU and depression. Prior studies have largely focused on the general population and treated IU as a single construct. In contrast, this study examines IU intensity and breadth and their effects on older adults’ depression. It also considers SSS as a potential moderator, providing a more nuanced understanding of the link of IU and depression and offering practical implications. Methodologically, GAM was employed to explore relationships without assum- ing linearity, revealing that associations can be linear or nonlinear depending on the sub-sample. This suggests the Goldilocks hypothesis warrants further investigation with advanced methods. Additionally, the study is among the few to use publicly available national surveys, highlighting the value of large-scale datasets for research in this area. While this study provided empirical evidence from a large-scale dataset, it has several limitations. First, although using existing large-scale surveys offers numerous benefits, as outlined earlier, one limitation is that these surveys may not be tailored to meet all the specific objectives of a par- ticular research study (Fan & Chiang, 2025; Fan, 2025). For example, the CFPS series only examines five specific types of IU. Future research could expand this scope to encompass a broader range of online activities, allowing for a more com- prehensive understanding of IU breadth among older adults. Additionally, the measurement of IU intensity is limited to the overall duration. Future studies should disaggregate usage time by activity type to explore how different online engagements and their duration influence depression in later life. Such an approach would provide a more nuanced depic- tion of the relationship between IU and depression, enabling more targeted policy and practical recommendations. More- over, it should be noted that IU intensity was measured as daily online duration, whereas IU breadth was measured as the number of activity types engaged in during the past week. This difference in reference periods may introduce measurement error and reduce direct comparability between these two aspects of IU. Future research could align the measurement windows to strengthen the comparability. Finally, this study relies primarily on quantitative meth- ods to examine the association between IU and depression among older adults. Further qualitative research is required to explore the underlying mechanisms in greater depth. Inte- grating qualitative approaches in future studies would offer richer insights into the social, psychological, and contextual factors shaping this relationship, thereby contributing to a more holistic understanding of the phenomenon. Acknowledgements Thanks to all the editors and the reviewers for their useful feedback that improved this paper. Author contributions Liangjie Fan: Writing – original draft, Writing- reviewing & editing, Methodology, Formal analysis, Data curation, Conceptualization, Methodology, Software, Visualization. Funding This research received no specific grant from any funding agency, commercial or not-for-profit sectors. Data availability The data supporting the findings of this study are publicly available from the China Family Panel Studies (CFPS) at Peking University and can be accessed at h t t p : / / w w w . i s s s . p k u . e d u . c n / c f p s / . Researchers may obtain the dataset following the procedures outlined on the CFPS website. No additional data were generated for this study.

  Keywords: depression future intensity breadth older adults understanding explore among surveys large scale specific cfps online
• The Relationship between Excessive Internet Use and Depression: A Questionnaire-Based Study of 1,319 Young People and Adults (2010) · doi

  Future research is needed to corroborate the existing evidence and address the nature of the relationship between IA and depression: there is comorbidity between these conditions that needs greater investigation.

  Keywords: future needed corroborate existing evidence address nature relationship depression there comorbidity conditions needs greater investigation
• Longitudinal and Reciprocal Relationships Between Depression and Disability in Older Women Caregivers and Noncaregivers (2015) · doi

  PURPOSE OF THE STUDY: Depressive symptoms and disability each increase the risk of the other, yet few studies have examined reciprocal associations between these conditions in a single study, or over periods longer than 3 years.

  Keywords: purpose depressive symptoms disability increase risk examined reciprocal associations conditions single periods longer years
• Some Normative and Psychometric Data for the Geriatric Depression Scale and the Cognitive Failures Questionnaire from a Sample of Healthy Older Persons (2004)

  Estimates of the prevalence of depression in older persons vary widely, depending on the diagnostic criteria and measures used, and the population tested, however, prevalence rates of between 10% and 19.

  Keywords: prevalence estimates depression older persons vary widely depending diagnostic criteria measures used population tested rates
• Women Veterans, a Population at Risk for Fibromyalgia: The Associations Between Fibromyalgia, Symptoms, and Quality of Life (2017) · doi

  To focus on the complex interrelationships between pain, fatigue, sleep, and depression, a follow-up study with a larger sample powered for more complex statistical analyses is warranted.

  Keywords: complex focus interrelationships pain fatigue sleep depression follow larger sample powered statistical analyses warranted
• Trends in depression prevalence in the USA from 2005 to 2015: widening disparities in vulnerable groups (2017) · doi

  Further research into understanding the macro level, micro level, and individual factors that are contributing to the increase in depression, including factors specific to demographic subgroups, would help to direct public health prevention and intervention efforts.

  Keywords: level factors further understanding macro micro individual contributing increase depression including specific demographic subgroups help
• Beyond major depression (2005) · doi

  RESULTS: Challenges to the utility of 'major depression' are provided by examining its conceptual model, its validity, its utility and the limited information generated in aetiological and treatment efficacy studies.

  Keywords: utility challenges major depression provided examining conceptual model validity limited information generated aetiological treatment efficacy
• Selective Serotonin Reuptake Inhibitor Discontinuation (2007) · doi

  Disparate findings from earlier studies may reflect aspects of study design, such as examining populations whose severity of depression varied widely or not controlling for important confounding factors.

  Keywords: disparate earlier reflect aspects design examining populations whose severity depression varied widely controlling important confounding