Depression Symptoms Declining Among Older Adults: Birth Cohort Analyses From the Rust Belt

Abstract

ObjectivesTo investigate potential birth cohort effects in depression symptoms in older adults. DesignPopulation-based prospective cohort. SettingSmall-town communities in Pennsylvania. ParticipantsThree thousand two hundred and twenty seven older adults (average baseline age = 71.6) born between 1902 and 1941. MeasurementsFour decade-long birth cohorts were the primary predictors in this study: 1902–1911, 1912–1921, 1922–1931, and 1932–1941. The outcome was symptoms of depression assessed at baseline and follow-up study visits using a modified Center for Epidemiologic Studies Depression Scale (mCES-D). The depression outcome was operationalized as: 1). A binary outcome of having greater than equal to 5 depression symptoms on the total mCES-D at any study visit, and 2). A continuous outcome of four factor-analyzed component scores of the mCES-D including depressed mood, anergia/hopelessness, withdrawal, and poor self-esteem. All analyses were jointly modeled with attrition and adjusted for age, sex, education, Mini Mental State Examination score, antidepressant medications, and total prescription medications. ResultsParticipants from more recently born cohorts were significantly less likely to have a study visit in which they reported greater than or equal to 5 depression symptoms, controlling for attrition. Specifically, in comparison to the 1902–1911 referent cohort, the 1912–1921 birth cohort was 43% less likely (odds ratio [OR] = 0.566, 95% confidence interval [CI]: 0.341–0.939), the 1922–1931 birth cohort was 63% less likely (OR = 0.0369, 95% CI: 0.215–0.632), and the 1932–1941 cohort was 79% less likely (OR = 0.205, 95% CI: 0.106–0.399). The cohort effect was most evident in the depressed mood and anergia/hopelessness symptom composites. ConclusionReduced rates of depression symptoms observed in successive birth cohorts of older adults may reflect compression of morbidity or other secular trends.