Cortisol in night-urine: Introduction of a research method in psychoneuroendocrinology

Cortisol is one of the major parameters investigated in psychoneuroendocrinological research, but the methods employed for sample collecting are often unsatisfactory, A suitable method of sample collection should allow for the integrative assessment of long-term changes of the HPA-system, should be non-invasive, and should not exceed the subject's compliance. The assessment of cortisol in night-urine fulfils these demands; although this method has been occasionally employed, it has not yet been described systematically, For the first time a detailed description is given here that allows for a standardized replication. In ten previous studies and three investigations of our own this method has been successfully applied to detect changes in the cortisol excretion of patients with endocrinological and psychiatric disorders as well as in subjects under conditions of psychosocial stress. The determination of cortisol in night-urine represents an ideal method for the assessment of changes in the basal HPA-activity in numerous areas of psychoneuroendocrinological research, e.g. field and screening studies in natural environment, clinical studies in psychiatry and especially follow-up studies in psychotherapy research.