Experimentally induced psychosocial stress in schizophrenia spectrum disorders: A systematic review

Background There is evidence that exposure to social stress plays a crucial role in the onset and relapse of schizophrenia; however, the reaction of patients with schizophrenia spectrum disorder (SSD) to experimentally induced social stress is not yet fully understood. Method Original research published between January 1993 and August 2015 was included in this systematic literature research. Social stress paradigms, reporting subjective responses to stress measures, plasma or saliva cortisol, or heart rate (HR) in patients with SSD were included. 1528 articles were screened, 11 papers (390 patients) were included. Results Three main findings were attained concerning chronically ill patients: (1) overall similar subjective responses to stress ratings between SDD patients and controls, (2) no group differences in cortisol response to psychosocial stress and (3) an increase in HR after the stress exposure was seen in patients and controls. The study examining first-episode patients found higher subjective responses to stress and lower stress-induced cortisol levels. Conclusion The results indicate that first-onset medication free patients may show differences in subjective responses to stress measures and cortisol release while chronically ill patients display no differences in subjective and cortisol response. This may be the correlate of a pathophysiological dysfunction of the hypothalamic-pituitary-adrenal axis prior or at the onset of SSD and a subsequent change in dysregulation during the course of the illness. Given the paucity of studies investigating psychosocial stress in SSD and the pathophysiological relevance of psychosocial stress for the illness, there is need for further research. (PROSPERO registration number: CRD42015026525)