Executive function and attentional bias as serial mediators in the relationship between frailty and depressive symptoms among older inpatients: A cross-sectional study.

Abstract

To examine the serial mediating effect of executive function and attentional bias in the relationship between frailty and depressive symptoms. Although the role of frailty in predicting depression has been well documented, the underlying mechanisms remain unclear. A cross-sectional study was conducted with 667 older inpatients aged 60-90years in the internal medicine wards of a hospital in China. 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. 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. 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. Healthcare providers should take executive function training and attentional bias regulation into consideration to reduce the detrimental effects of frailty on emotional well-being.