[Hypothalamic-pituitary-adrenal and hypothalamic-pituitary-thyroid axis findings in depressive disorder]

To find out whether the neuroendocrine abnormalities, that may be seen in major depressive disorder (MDD), differ during depression and remission periods, compared with the controls.

Twenty subjects, diagnosed as MDD according to DSM -IV, ICD-10, and 20 healthy controls were randomly selected and included in this study. Dexamethasone Suppression Test (DST) and Thyroid Releasing Hormone (TRH) test were performed and basal hormone levels were determined in all subjects.

All cortisol responses were found to be significantly higher in the patient group during depression period compared to the control group except at 16:00 before dexamethasone. Comparison of depression and remission periods revealed that all cortisole levels before and after dexamethasone were significantly higher in depression period. Thyroid Stimulating Hormone (TSH) responses to TRH, maximal TSH responses, change in maximal TSH level were significantly lower in the patient group compared with the controls. The rate of DST positivity was 70% in depression period and 5% in remission period. Blunted TSH response rate was 50% in depression period and 35% in remission period.

We found that while DST positivity in depression returned to normal during remission, blunted TSH response was consistent both during depression and remission.