The cortisol awakening response (CAR): facts and future directions.
Level 5 - mechanism / opinion, no new human data
Narrative review and theoretical synthesis without systematic methodology or primary human data.
PubMed 18854200 · doi:10.1016/j.ijpsycho.2008.03.014
What was done
Narrative review synthesizing published research on the neural regulation of the cortisol awakening response (CAR), moderating influences (including gender, health status, health behavior, and stress perception), and theoretical perspectives on its biological function.
What was found
The abstract reports no empirical data or quantitative statistics. It notes that the CAR is a distinct feature of the hypothalamic-pituitary-adrenal axis regulated by brain regions including the hippocampus, amygdala, prefrontal cortex, and suprachiasmatic nucleus, and proposes the hypothesis that anticipation of the upcoming day determines CAR magnitude.
Why it matters
The paper synthesizes physiological and psychological mechanisms regulating the post-awakening cortisol surge and formalizes the hypothesis that the CAR serves an anticipatory function for upcoming daily demands.
Limits
Narrative review design without systematic search criteria, meta-analytic pooling, or new primary empirical data. No quantitative outcomes, sample sizes, or study counts are reported in the abstract.
Cited by
- context Waking up right before an alarm clock is caused by an entrained morning cortisol spike rising to a threshold.
- supports Under the cortisol awakening response, cortisol levels peak around waking and then decline steadily over the remainder of the day.