PURPOSE: To examine whether optimism/pessimism reliably predicts depression and whether such function is stable also in older age.
METHOD: In a prospective study, we observed a representative sample of n = 4,046 primary care patients over 5 years. The Life Orientation Test (LOT-R, measuring optimism/pessimism) and the Depression-Screening Questionnaire were applied. Medical diagnoses were recorded by the treating physician in a structured medical interview.
RESULTS: Depression could only be predicted by LOT-R scores in younger-age cohorts. In older adults, test stability and predictive accuracy of optimism/pessimism were markedly reduced, while somatic comorbidity gained importance as a predictor.
CONCLUSIONS: Predictive value of screening measures for mental disorders may be specific in older age due to lower trait stability and age-specific psychometric limitations as well as age-related changes in relevant predictors.