The hypothalamic-pituitary-adrenal axis (HPA axis) is the neuroendocrine system that regulates the stress response in mammals. Its basic functioning: in the face of a threat, the hypothalamus releases CRH (corticotropin-releasing hormone), the pituitary responds with ACTH (adrenocorticotropic hormone), and the adrenal glands secrete cortisol, which prepares the body to fight or flee.
Under normal conditions, the system is self-regulating: cortisol itself, once in circulation, feeds back to the hypothalamus and pituitary, signaling that the response is already active, and returns to baseline levels within hours. The problem is chronic dysregulation: when stress is persistent or trauma is severe, the HPA axis remains altered for years, sometimes for life.
Central findings in transgenerational trauma link FKBP5, glucocorticoid receptor methylation, and HPA axis regulation. Yehuda et al. (2014) documented that offspring of Holocaust survivors with PTSD show specific patterns of cortisol receptor regulation that differ from both controls and their own traumatized parents — a pattern biologically consistent with the transgenerational transmission of trauma.
Understanding the HPA axis allows us to translate clinical experiences (“I feel my body is always on alert,” “I can’t rest”) into verifiable physiological language, and to understand why certain early wounds leave marks that do not respond solely to verbal therapy.
Bibliography
- Influences of maternal and paternal PTSD on epigenetic regulation of the glucocorticoid receptor gene in Holocaust survivor offspring — Rachel Yehuda et al.. American Journal of Psychiatry, 171(8), 872-880, 2014.
- Holocaust Exposure Induced Intergenerational Effects on FKBP5 Methylation — Rachel Yehuda et al.. Biological Psychiatry, 80(5), 372-380, 2016.
- The Body Keeps the Score — Bessel van der Kolk. Eleftheria, 2015.
These books are in the reference library that nourishes Constelando el Origen.
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Related terms
Cortisol
The primary human glucocorticoid. A stress hormone released by the adrenal glands. Its baseline and response levels are altered in trauma victims and in children of survivors.
See entryFKBP5 (stress gene)
A gene that regulates the sensitivity of the glucocorticoid receptor to cortisol. Its epigenetic modifications are one of the central findings in the transgenerational transmission of trauma.
See entryEpigenetics
The study of changes in gene expression that do NOT alter the DNA sequence, are heritable, and can be activated by life experiences—including trauma.
See entryTransgenerational trauma
Pain or trauma unprocessed by one generation that is transmitted—psychically, somatically, and, according to recent evidence, epigenetically—to subsequent generations.
See entryInterrupted bonding
An early rupture in the bond between a child and their primary attachment figure—usually the mother—that leaves a deep systemic imprint.
See entryA session that names what hurts
If you recognize this dynamic in your own story, a Family Constellation can reveal its origin and what movement brings order to it. Daniela accompanies each case with respect.
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