Psychological, endocrine, central nervous and genetic predictors of chronic stress responses in daily life - a prospective-longitudinal quasi-experiment

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Chronic stress is a significant risk factor for several disorders. However, while there is ample evidence for this association between stress and malady, the biopsychological mechanisms mediating this link are still poorly understood. Based on the allostatic load model we propose investigating relevant mechanisms in a project with a prospective-longitudinal and quasi-experimental design.This design requires a research cohort that will be exposed to a long-lasting and significant stress phase in a determined future period. Moreover, it needs to allow for the recruitment of a control group. These requirements are met to a high degree by the (preparation for) the erste juristische Staatsprüfung. This state examination is one of the most stressful academic exam periods in the German university system. On average students start one year prior to the exam with an intense preparation that substantially influences experience and behavior in the following months. We plan including 500 law students, n=250 from the University of Regensburg (cohort A) and n=250 from other Bavarian law schools (cohort B). Half of the subjects in each cohort will be studied over the 14-months stress period while the other half will be studied over an equally long period without particular stress exposure.The individual experience will be measured with repeated ambulatory assessments. The use of smartphones and web-based platforms allows assessing stress related variables in real life, in real time, repeatedly and with high ecological validity. On the psychoendocrine level we plan a repeated collection of saliva and hair samples to assess changes in cortisol secretion. The allostatic load model proposes that acute and chronic stress responses are significantly modulated by interindividual differences. To identify such differences, the predictive value of stress related psychological traits and of health behavior will be assessed. In order to explore the predictive value of neuronal responses to acute stress, subjects will be exposed to a fMRI stress paradigm that has been recently developed by our group. In addition, genetic factors have a significant influence on stress responses. In an analysis fulfilling all requirements for a gene-environment-(quasi-)experiment we intend to focus on genetic variability in the neuropeptide S-system. NPS has pronounced anxiolytic effects and a significant influence on stress response systems has been convincingly documented. The general aim of the present study is to significantly contribute to the identification of mechanistically relevant predictors of biopsychological chronic stress responses in humans. In our view, the proposed prospective-longitudinal and quasi-experimental project that plans utilizing a synergistic combination of innovative methods is a very promising approach to achieve this goal.