RESUMO
AIMS AND OBJECTIVES: To examine the serial mediating effect of executive function and attentional bias in the relationship between frailty and depressive symptoms. BACKGROUND: Although the role of frailty in predicting depression has been well documented, the underlying mechanisms remain unclear. DESIGN: A cross-sectional study was conducted with 667 older inpatients aged 60-90 years in the internal medicine wards of a hospital in China. METHODS: Attentional bias, frailty and depressive symptoms were assessed using the Attention to Positive and Negative Information Scale, the Physical Frailty Phenotype and the 5-item Geriatric Depression Scale. Executive function was measured using 3 tests, including digital backward, category Verbal Fluency Test and Trail Making Test. The study followed the STROBE guideline. RESULTS: The latent profile analysis (LPA) identified four patterns of attentional bias, namely "no positive bias & no negative bias" (class 1, 9.3%), "minor positive bias & no negative bias" (class 2, 48.0%), "major positive bias & minor negative bias" (class 3, 25.6%) and "major positive bias & no negative bias" (class 4, 17.1%). Regression analysis found that frailty was associated with depressive symptoms. Frailty was also negatively associated with executive function, which was a protective factor for attentional bias class 1, 2 and 3 with reference to class 4. Attentional bias class 1 and 2 but not class 3 was associated with depressive symptoms with reference to class 4. The joint significance test confirmed executive function and attentional bias as serial mediators linking frailty to depressive symptoms. DISCUSSION: Unlike robust older adults who have the age-related positivity effect, frail older adults have attentional bias deficits due to executive dysfunction, and consequently experience clinically relevant depressive symptoms. RELEVANCE TO CLINICAL PRACTICE: Healthcare providers should take executive function training and attentional bias regulation into consideration to reduce the detrimental effects of frailty on emotional well-being.