CO₂ challenge-evoked hormonal changes predicting TSST changes in cortisol and subjective distress

Area of Science:

• Psychophysiology
• Neuroendocrinology
• Stress Research

Background:

• Stressor response is crucial for psychopathology development, but the exact mechanisms remain unclear.
• The Trier Social Stress Test (TSST) and 35% CO2 Challenge are common laboratory stressors.
• The 35% CO2 Challenge is primarily used for subjective anxiety responses, while TSST assesses cortisol reactivity.

Purpose of the Study:

• To investigate the predictive effects of the 35% CO2 Challenge on outcomes from the TSST.
• To assess hormonal (cortisol, testosterone) and subjective distress responses to both stressors.
• To examine potential sex differences in stressor response prediction.

Main Methods:

• 189 mixed-sex, college-aged participants underwent the 35% CO2 Challenge, followed by the TSST days later.
• Hormonal levels (cortisol, testosterone) and subjective distress (stress, anxiety, fear) were measured.
• Statistical analyses explored predictive relationships between the two stressor responses.

Main Results:

• No significant testosterone-cortisol interaction effects on stress responses were observed in females.
• In males, the interaction between testosterone and cortisol following the 35% CO2 Challenge predicted TSST-evoked subjective stress, anxiety, and fear.
• Specifically, higher testosterone predicted greater subjective distress when cortisol levels were low (one standard deviation below the mean).

Conclusions:

• The findings support the dual-hormone hypothesis, indicating a complex interplay between hormones in stress reactivity.
• The 35% CO2 Challenge shows potential as a predictor of responses to other laboratory stressors like the TSST.
• This suggests the 35% CO2 Challenge could be a valuable tool in broader laboratory stress response research.