Relationships between salivary cortisol, symptom severity and lifestyle factors in chronic schizophrenic patients

Abstract

BACKGROUND: This study examined the relationships between diurnal cortisol patterns and perceived stress, physical activity, symptom severity, and daily functioning in patients with chronic schizophrenia. METHODS: The participants were 149 Chinese patients with chronic schizophrenia. Diagnostic assessments of body-mass index (BMI), psychotic symptoms and neurological deficits were made, and self-reported measures of physical activity, perceived stress, and daily functioning were recorded. Diurnal cortisol slope was derived from the salivary cortisol measures collected upon waking, 30 min after waking, before lunch, and before bedtime. A path modeling analysis was performed to investigate the relationships of the diurnal cortisol slope and its antecedents and outcomes. RESULTS: Higher levels of perceived stress, higher BMI, and less physical activity predicted lower waking cortisol and flattened diurnal cortisol slopes. Controlling for age and gender, flattened diurnal cortisol slopes were significantly associated with higher levels of depressive symptoms, cognitive symptoms, motor deficit, and poorer daily functioning. DISCUSSIONS: The results support the neural diathesis–stress model and highlight the importance of the hypothalamic–pituitary–adrenal axis in mediating the effects of stress and symptom severity among patients with chronic schizophrenia. The practical implications of the findings are discussed. LEARNING OBJECTIVES: 1. Communicate the neural diathesis–stress model and highlight the importance of the hypothalamic–pituitary–adrenal axis 2. Describe the associations between lifestyle factors and diurnal cortisol patterns in schizophrenic patients