Exposure with response prevention (ERP) is an established treatment for patients with obsessive-compulsive disorder (OCD) and also an interesting model to characterize neuroendocrine response to psychological stress. However, so far few studies have assessed hypothalamic-pituitary-adrenocortical (HPA) function during ERP and results are inconsistent. In 15 patients with OCD we repeatedly measured salivary cortisol and subjective units of distress (SUD) on two consecutive afternoons. The first day served as a comparison condition; on the second day the very first session of ERP took place. While SUD were significantly increased during ERP versus the comparison day, salivary cortisol was statistically indistinguishable between ERP and comparison conditions before, during and after ERP. Thus, despite considerable psychological stress no increase of cortisol was observed. This response pattern to ERP in OCD patients needs further research.
