Judgement of the hypothalamic-pituitary-adrenocortical function in psychiatric patients by betamethasone-induced cortisol suppressibility

Summary Betamethasone induced cortisol suppressibility was examined in 62 drug free consecutively admitted psychiatric inpatients. Betamethasone was choosen instead of the commonly used dexamethasone, because its double half-life compared to dexamethasone and its higher tissue availability. After a base-line evaluation with blood samples drawn at 8 a.m., 4 p.m., and 11 p.m., 0.5 mg or 1.0 mg betamethasone was given orally at 11 p.m. Postbetamethasone cortisol as well as betamethasone blood levels were then measured at the same time points as on the baseline day. In the groups receiving 1.0 mg betamethasone non-depressed patients had significantly (p<0.05) lower postbetamethasone cortisol levels than depressed patients for each time point measured whereas 0.5 mg betamethasone did not differentiate depressed from non-depressed patients. Patients with other depressions like schizoaffective psychosis -depressive subtype- or organic brain syndrome with depressive symptomatology demonstrated similar postbetamethasone cortisol profiles as the group of patients with major depression. Betamethasone plasma concentrations differed significantly (p< 0.001) with respect to the oral dosage with higher values for the 1.0 mg betamethasone groups.