Relationship between age and aspects of depression: consistency and reliability across two longitudinal studies

In this study, the authors examined cross-sectional and longitudinal age and gender differences in each of the Center for Epidemiological Studies Depression Scale's 4 subscales of depressive symptomatology. Two independent studies (Sample 1 = 2,076; Sample 2 = 943) were used for purposes of establishing stability of findings. Results indicate a reasonable degree of stability among adults under 70 years of age. However, there were significant age-related increases in somatic symptoms and lack of well-being after approximately 70 years of age, whereas symptoms related to depressed affect and interpersonal problems remained stable. Notably, depressive affect symptoms remained stable given significant age-related somatic changes. The addition of comorbid physical illness to the analysis did not reduce the association between age and depressive symptoms, indicating that part of the association was not substantially accounted for by physical health.