Longitudinal Association between Late-Life Depression (LLD) and Frailty: Findings from a Prospective Cohort Study (MiMiCS-FRAIL).

Objectives: The aim of the present study was to investigate whether late-life depression (LLD) is associated with incident frailty over time.

Design: Prospective cohort study, one-year follow-up.

Setting: Geriatric outpatient clinic, Southwestern of Brazil.

Participants: 181 follow-up participants aged 60 years or over.

Measurements: Depressive disorders were classified as Major Depressive disorder (MDD) or Subthreshold Depression (STD) according to DSM-5 criteria. Depressive symptoms were assessed with validated versions of 15-item Geriatric Depression Scale (GDS-15) and 9-item Patient Health Questionnaire (PHQ-9). We performed binary logistic regressions to estimate the odds ratio (OR) for frailty in LLD adjusting for multiple confounders. Participants who were frail at baseline were excluded from the analyses according to measures of frailty (FRAIL questionnaire and 36-item Frailty Index, FI-36). We also estimated the risk ratio or relative risk (RR) and the risk difference (RD) for incident frailty.

Results: We observed a 2 to 4-fold increased risk for incident frailty among participants with LLD. The presence of a depressive disorder was significantly associated with the onset of frailty (adjusted OR for FRAIL and FI-36: 3.07 [95% CI = 1.03 - 9.17] and 3.76 [95% CI = 1.09 - 12.97], respectively. Notably, the risk for frailty due to LLD was significantly higher with the FI-36 compared to the FRAIL (RR: 3.03 versus 2.23). RD was of 17.3% and 12.7% with the FRAIL and the FI-36, respectively.

Conclusion: Our data support the association between LLD and incident frailty over one year among geriatric outpatients, reinforcing longitudinal evidence from population-based studies.