Depressive symptoms and daily living dependence in older adults with type 2 diabetes mellitus: the mediating role of positive and negative perceived stress

BACKGROUND: Higher stress is associated with higher levels of depression and instrumental-activities-of-daily-living (IADL) dependence, and depression is strongly associated with specific IADL disabilities. Accordingly, the aim of this study was to investigate the mediating effect of perceived stress on the association between depression and IADL dependence among older adults with diabetes mellitus (DM).

METHODS: We examined baseline data collected from a longitudinal study that recruited 110 patients with DM aged ≥ 65 years from the endocrinology outpatient clinic of a district hospital. The instruments used for our measurement processes comprised a demographic data sheet and Chinese versions of the Perceived Stress Scale (PSS), the short form of the Geriatric Depression Scale (GDS-S), and the Lawton IADL Scale. We assessed the mediating effects of positive perceived stress (PPS) and negative perceived stress (NPS) after controlling for five covariates by using a regression-based model run through the SPSS macro PROCESS.

RESULTS: We observed negative correlations between GDS-S scores and PPS and between PPS and IADL dependence; we noted positive correlations between GDS-S scores and NPS and between NPS and IADL dependence (all P < 0.01). The indirect effect is coefficient = 0.12, [95% confidence interval = (0.0, 0.33)], suggesting that PPS achieves a mediating effect between depressive symptoms and IADL dependence. However, the NPS does not achieve a mediating effect in the relationship between depressive symptoms and IADL dependence (coefficient = 0.06, 95% CI = - 0.03, 0.15).

CONCLUSIONS: Personal PPS mediates the association between depression and IADL dependence in older adults with DM. This finding suggests that providing patients with psychological education to promote their PPS may help prevent their functional decline.