Associations Between Subjective and Objective Cognitive Decline and Depressive Symptoms in Community-Dwelling, Older...

The potential role of cognitive decline as a risk factor for depression has been inconsistently reported across studies. This study aimed to clarify the associations between subjective and objective cognitive decline and depressive symptoms in community-dwelling older adults.

Data from 1935 participants (mean age, 77.9 ± 5.3 years; male, 39.8%) in the Takashimadaira Study were analysed. Depressive symptoms were assessed using the modified Geriatric Depression Scale (mGDS-15). Subjective cognitive decline (SCD) was measured using the self-administered dementia checklist, and objective cognitive function was assessed using the Mini-Mental State Examination (MMSE). Associations of subjective and objective cognitive decline with overall depressive symptoms and with depressive symptom subscales ('unhappiness', 'apathy and anxiety' and 'hopelessness') were examined using multivariate logistic regression analysis.

Significant depressive symptoms were present in 14.9% of the participants. SCD was independently associated with depressive symptoms (odds ratio: 5.10, 95% confidence interval: 3.45-7.53, p < 0.001). SCD was also positively associated with all depressive symptom subscales. In contrast, MMSE scores showed no significant association with overall depressive symptoms, although lower MMSE scores were associated with the 'apathy and anxiety' subscale.

SCD was associated with a broad range of depressive symptoms, from emotional symptoms to motivational aspects. In older people with SCD, it is important to be aware of the potential presence of underlying depressive symptoms to facilitate their early detection, with due consideration of the bidirectional relationship between SCD and depressive symptoms.