Investigation of the Endogenous Stress Response System in Patients with Chronic Schizophrenia.

OBJECTIVE

Cardiophysiological and neuroendocrine studies suggest that the two components of the endogenous stress response system, the sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenal (HPA) axis, are dysregulated in patients with schizophrenia. However, cardiophysiological measures are influenced by several confounding factors and the secretion of α-amylase in saliva is believed to represent a more reliable index of SNS activity. Therefore, to characterize the functional status of the SNS and HPA axis in schizophrenia we explored the concomitant salivary secretion of cortisol and α-amylase.

METHODS

Saliva cortisol and α-amylase levels were measured after awakening in 30 patients with chronic schizophrenia and 22 healthy subjects.

RESULTS

After awakening, saliva cortisol increased in a similar way in both patients and healthy controls, while saliva α-amylase concentrations showed a clear-cut decrease in healthy subjects but not in patients with schizophrenia. No significant correlation emerged between biochemical measures and patients' demographic or psychopathological characteristics.

CONCLUSIONS

These findings demonstrate normal activity of the HPA axis with an enhanced SNS tone, which suggests a functional dissociation of the two components of the endogenous stress response system in patients with chronic schizophrenia. The pathophysiological significance of such dysregulation needs further studies to be clarified.