HPA axis activation by a socially evaluated cold-pressor test.

The cold-pressor test (CPT) in which subjects immerse their hand in ice water is among the most commonly used laboratory stressors. While the CPT elicits strong sympathetic nervous system activation, cortisol elevations indicative for the reactivity of the hypothalamus-pituitary-adrenal (HPA) axis are moderate to low in response to the CPT. In the present study, we assessed whether cortisol responses to the CPT can be increased by adding social-evaluative elements. Therefore, 70 healthy young men immersed their hand in ice or warm water and were watched by a woman and videotaped during hand immersion or not. While the standard CPT and the socially evaluated cold-pressor test (SECPT) led to comparable increases in blood pressure and subjective stress ratings, saliva cortisol elevations and the proportion of subjects showing a saliva cortisol response (defined as increase >2nmol/l) were significantly higher after the SECPT. Social evaluation during hand immersion in warm water did not affect saliva cortisol levels suggesting that both social evaluation and a challenge are required for HPA axis activation. These findings indicate that the incorporation of social-evaluative elements increases HPA axis responses to the CPT. The SECPT can serve as a tool for future stress research.