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.
© 2015 S. Karger AG, Basel.