The Reciprocal Relationship Between Depression and Physical Morbidity: The Role of Subjective Age
Objectives: The study aims to examine whether the reciprocal effects of physical morbidity and depression are moderated by subjective age—that is, individuals’ perception of themselves as young or old. Method: Data from the first two waves of the Midlife in the United States study (1995–6, T1; 2004–6, T2; http://midus.wisc.edu/) were analyzed using a cross-lagged design. We assessed 3,591 individuals who participated in both waves and provided full data on all the relevant variables (mean age at T1 = 47.4). Depression and the number of chronic illnesses (the indicator of physical morbidity) were measured at both waves and were tested as predictors and outcomes in a cross-lagged model. The moderating role of subjective age was assessed by examining whether T1 variables interacted with subjective age in predicting T2 outcomes. Results: Subjective age moderated the T1 depression–T2 morbidity relationship, so that the relationship was stronger for those with older subjective age. Subjective age did not moderate the T1 morbidity–T2 depression relationship. Conclusion: Older subjective age could be a risk factor for experiencing greater physical morbidity following depression.