Background: Patients with schizophrenia may differ from healthy controls by having dysregulated physiological responses to stress. Our objective was to determine the extent to which cortisol reaction can discriminate between controls and schizophrenia patients while controlling for symptom severity, personality, body mass index (BMI) and smoking.
Method: 30 chronic schizophrenia patients and 30 matched controls underwent a modified version of the Trier Social Stress Test (TSST), consisting of public speaking and mental arithmetic. Heart rate, blood pressure, and salivary cortisol were measured repeatedly throughout the TSST. In addition, participants completed the NEO Personality Inventory (NEO-FFI), and were interviewed with the Brief Psychiatric Rating Scale (BPRS).
Results: Both groups had a significant increase in heart rate and mean arterial pressure following the TSST. Results of a logistic regression suggests that patients can be discriminated from controls with a smaller change in cortisol between baseline and 15 min post-TSST, controlling for BMI and severity of positive symptoms. There was a trend for lower overall cortisol secretion in patients.
Conclusions: Despite demonstrable effects of the stressor on cardiac measures, schizophrenia patients tend to have smaller acute cortisol reaction to psychosocial stress. The significance of this conclusion for vulnerability-stress models of schizophrenia is discussed.