First-episode psychosis (FEP) patients show hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis, but the mechanisms leading to this are still unclear. The aim of this study was to investigate the role of stress and antipsychotic treatment on diurnal cortisol levels, and on cortisol awakening response, in FEP. Recent stressful events, perceived stress and childhood trauma were collected in 50 FEP patients and 36 healthy controls using structured instruments. Salivary cortisol was obtained at awakening, at 15, 30, and 60 min after awakening, and at 12 and 8 pm. Patients experienced more recent stressful events, perceived stress and childhood trauma than controls (p < 0.001). Patients had a trend for higher diurnal cortisol levels (p=0.055), with those with less than two weeks of antipsychotics showing significantly higher cortisol levels than both patients with more than two weeks of antipsychotics (p=0.005) and controls (p=0.002). Moreover, patients showed a blunted cortisol awakening response compared with controls, irrespectively of antipsychotic treatment (p=0.049). These abnormalities in patients were not driven by the excess of stressors: diurnal cortisol levels were negatively correlated with the number of recent stressful events (r=−0.36, p=0.014), and cortisol awakening response was positively correlated with a history of sexual childhood abuse (r=0.33, p=0.033). No significant correlations were found between perceived stress or severity of symptoms and cortisol levels, either diurnal or in the awakening response. Our study shows that antipsychotics normalize diurnal cortisol hypersecretion but not the blunted cortisol awakening response in FEP; factors other than the excess of psychosocial stress explain HPA axis abnormalities in FEP.

Antipsychotic treatment potentially contributes to the brain structural changes observed in psychosis. Future research should take into account these potential effects, and use adequate sample sizes, to allow improved interpretation of neuroimaging findings in these disorders.

Background Reduced brain-derived neurotrophic factor (BDNF) levels have been reported in the serum and plasma of patients with psychosis. The aim of this study was to investigate potential causes and consequences of reduced BDNF expression in these patients, by examining the association between BDNF levels and measures of stress, inflammation and hippocampal volume in first-episode psychosis. Methods BDNF, interleukin (IL)-6, and tumour-necrosis-factor (TNF) alpha mRNA levels were measured in leukocytes of 49 first-episode psychosis patients (DSM-IV criteria) and 30 healthy controls, recruited between January 2006 and December 2008. In the same subjects, we measured salivary cortisol levels, and collected information about psychosocial stressors (number of childhood trauma, number of recent stressors, and perceived stress). Finally, hippocampal volume was measured, using brain MRI, in a subsample of 19 patients. Results Patients had reduced BDNF (effect size d=1.3, p<0.001) and increased IL-6 (effect size d=1.1, p<0.001) and TNF-alpha (effect size d=1.7, p<0.001) gene expression levels, when compared with controls, as well as higher levels of psychosocial stressors. A linear regression analysis in patients showed that a history of childhood trauma and high levels of recent stressors predicted lower BDNF expression through an inflammation-mediated pathway (adjusted R square=0.23, p=0.009). In turn, lower BDNF expression, increased IL-6 expression, and increased cortisol levels, all significantly and independently predicted a smaller left hippocampal volume (adjusted R square=0.71, p<0.001). Conclusions Biological changes activated by stress represent a significant factor influencing brain structure and function in first-episode psychosis, through an effect on BDNF.

This study investigated the relationship between cortisol secretion and hippocampal volume in first-episode psychosis and healthy controls. Hippocampal volume was measured by magnetic resonance imaging (MRI) in 24 first-episode psychosis patients and in 18 healthy controls, together with diurnal cortisol levels. Twelve patients received a second MRI scan at 3-month follow-up. Diurnal cortisol levels were inversely correlated with left hippocampal volume in patients, both at baseline and at follow-up, while no correlation was found in controls. Our findings suggest that smaller hippocampal volume in first-episode psychosis can partly be explained by stress-related processes in the brain, as measured by cortisol hyper-secretion.