When the mind says one thing, but the HPA axis says another: Lack of coherence between subjective and neuroendocrine stress response trajectories in healthy men.

Psychological stress triggers the release of cortisol following the activation of the hypothalamic-pituitary-adrenal (HPA) axis and elicits concomitant subjective responses. Coherence among the stress response systems is theoretically expected, presumably to optimize the organism's response to environmental challenges, but has received little empirical support possibly due to the assumption of linear associations. The present study examined the associations between cortisol responses to the Maastricht Acute Stress Test (MAST) and concomitant subjective stress responses as well as mood states over the past weeks in 133 healthy men. Latent class growth analysis (LCGA) was applied on individual cortisol and subjective stress responses to identify homogeneous response trajectories within the larger heterogeneous population and enable testing non-linear relationships while retaining the temporal resolution of the stress responses. LCGA revealed four latent cortisol response classes, labeled as mild responders (n = 15), moderately-low responders (n = 46), moderately-high responders (n = 48), and hyper responders (n = 24). These latent classes were not associated with concomitant subjective stress responses. Similarly, the three distinct latent classes capturing the variability in subjective stress responses were also not associated with concomitant cortisol responses. Experiencing higher levels of stress over the previous weeks, however, increased the likelihood of exhibiting a hyper cortisol stress response profile. Positive and negative affective states, and anxious and depressive symptomology over the previous weeks were not associated with cortisol response trajectories. Contrary to previous findings supporting a quadratic association in healthy females, our results do not support the response coherence hypothesis in healthy males subjected to the MAST, but suggest that recent levels of perceived stress may influence the cortisol response to acute stress.