A network analysis of depressive symptoms in adults with and without diabetes: findings from the Irish longitudinal study on ageing

Objectives: This study aimed to estimate networks of depressive symptoms among Irish adults with and without diabetes at two time points and compare between the two groups at each time point using data from the Irish Longitudinal Study on Ageing (TILDA).

Methods: Participants were from Wave 1 (2009-2011) and Wave 4 (2016) of TILDA, with n = 639 participants with diabetes and n = 7,837 without diabetes at Wave 1, and n = 1,151 with diabetes and n = 4,531 without diabetes at Wave 4. Depressive symptoms were measured using the 8 items of the Center for Epidemiologic Studies Depression Scale. Network psychometric analysis was used to examine symptom centrality, symptom-level associations, and network comparisons at each time point.

Results: Stable, strongly connected networks emerged for people with and without diabetes at both time points. The symptoms of feeling depressed, feeling like everything's an effort, not enjoying life, feeling sad, and couldn't get going were the most central nodes in all networks, which did not differ between people with and without diabetes. However, for people with diabetes, the network was more densely connected at Wave 4, when the sample was predominately people with newly diagnosed diabetes. Furthermore, the relationship between 'felt lonely' and 'couldn't get going' and between 'not enjoying life' and 'sad' was significantly stronger for people with diabetes than for those without.

Conclusions: This study provides a more detailed understanding of the structure of depressive symptoms at two time points in older Irish adults with and without type 1 or type 2 diabetes.