The role of patient pain and physical function on depressive symptoms in couples with lung cancer: A longitudinal dyadic analysis

Drawing on the Developmental-Contextual Model (Berg & Upchurch, 2007), we examined the association between changes in patient physical health (pain severity and physical function) and changes in depressive symptoms in couples with lung cancer over a 12-month period. Patients and their spouses or partners (n = 77) were recruited using rapid case ascertainment and completed five waves of data collection (baseline, 3, 6, 9, and 12 months). Multilevel modeling was used to examine aggregate and time-varying effects of patient physical health on depressive symptoms. Results indicated that for patients and spouses, patient-rated mean pain severity was significantly positively associated with patient and spouse depressive symptoms and patient-rated mean physical function was significantly negatively associated with patient and spouse depressive symptoms. More importantly, increases in patient pain severity and declines in patient physical function were significantly associated with increases in patient depressive symptoms. However, only declines in patient physical function were significantly associated with increases in spouse depressive symptoms. These timevarying effects remained even when controlling for patient gender, patient age, patient stage of disease, spouse physical health, and relationship quality. Findings suggest the importance of examining the changing illness context on the couple as a unit and the complexity of interpersonal processes in the presence of a life-threatening illness.