Dexamethasone suppression test (DST): Simultaneous Investigation of confounding variables predicting Individual extend of suppression in depression – A multiple regression analysis

Despite of the longstanding use of the DST in research the impact of confounding variables in individual patients is still undetermined, supposedly due to a lack of studies examining parallel the influence of specific impact factors. Moreover, the traditional outcome of the DST in clinical application with a dichotomous classification as „suppressors“ vs. „nonsuppressors“ ignores information concerning individual dysregulation of HPA-system as extend of suppression relative to pre-dexamthasone cortisol levels. Therefore we conducted a study with simultaneous investigation of the following aspects as possible predictor variables for individual extend of suppression in DST: gender, age, body mass index, waist-to-hip-ratio, age of onset, number of former depressive episodes, severity of current episode, existence of psychotic symptoms and family history of affective disorders as well as comorbidity. To identify predictor variables with individual extend of explained variance in cases of significant predictors multiple regression analysis is a well-established statistical method. To enhance statistical test power we will include a minimum of N=75 subjects. Since data collection is still in progress, results will be presented at the congress.