Background: The aim of this work was to investigate alterations of plasma corticotropin-releasing factor (CRF) levels in depressive states. We have also measured plasma cortisol and corticotropin (ACTH) concentrations and examined their correlation with the peripheral CRF values.
Methods: Thirty-six outpatients from the psychiatric department of a Barcelona hospital who were diagnosed as having major depressive disorder (n = 26) and dysthymic depressive disorder (n = 10) were studied. Among the major depressed patients, 10 suffered from severe depressive disorder and 16 from mild or moderate depressive disorder. The comparison group consisted of 17 healthy volunteers. Cortisol, ACTH, and CRF concentrations were determined by iodine-125 radioimmunoassay; CRF measurements were performed on C18 extracted samples.
Results: CRF and cortisol plasma concentrations were significantly higher in major depression and dysthymia than in the comparison group. The major depressed patients did not show significantly different CRF and cortisol levels than the dysthymic. Severe major depressive disorder exhibited significantly higher CRF plasma levels than the mild or moderate episodes. Plasma cortisol and CRF concentrations correlated significantly.
Conclusions: The results obtained indicate that plasma CRF values are altered in depressive disorders and suggest that these determinations could be important for understanding the pathophysiology in affective illness.