Project Summary/Abstract The objective of the MIDUS Daily Diary Project is to determine how short term fluctuations in daily stress processes impact longer-term health and well-being throughout midlife and later adulthood. Specific aims are: (1) To assess changes in multiple aspects of daily stressors and daily well-being across three occasions spanning 20 years; (2) To investigate how daily stress processes disrupt diurnal rhythms of salivary cortisol and alpha amylase; and (3) To enhance data from the MIDUS cognitive project by adding new assessments of everyday cognition: unconstructive repetitive thinking (intrusive thoughts) and memory failures. These aims will be addressed by conducting the third wave of longitudinal data collection from participants who participated in the previous MIDUS I & II Diary. The longitudinal sample will consist of 1000 individuals selected from the MIDUS random digit dialed (RDD) participants and 200 participants from the African-American Milwaukee sample. The collection protocol will continue to use an 8-day telephone diary study of daily stressors and well- being combined with multiple assessments of saliva (4 occasions × 4 days) to ascertain salivary cortisol and a new biomarker for this project: salivary alpha amylase (sAA). The MIDUS Daily Diary Project will continue to incorporate the rich measures (sociodemographic, personality, cognitive) obtained in other MIDUS projects in our analyses to study how they relate to changes in daily stress processes. This project will also use information obtained from the biomarker, gene expression and neuroscience projects to examine how changes in daily stress processes predict changes in various indicators of health (e.g., allostatic load, inflammatory processes, neuroendocrine regulation, cardiovascular risk).