PTSD: How Chronic Cortisol and Hippocampal Loss Keep the Trauma Alive

The physiology

PTSD is the condition that results when traumatic fear memories fail to be contextualised and filed. The amygdala, which encodes threat memories, becomes chronically hyperreactive — responding to reminders of the trauma with the same full-intensity fear response as the original event. The hippocampus, which normally provides the contextual information that tells the amygdala a stimulus is a memory rather than a current threat, atrophies under chronic cortisol exposure — losing volume measurably on MRI. Without hippocampal context, every trigger replays the original terror.

"It's really well documented that individuals with PTSD have areas of brain hypometabolism."

PET imaging consistently shows hypometabolism in the prefrontal cortex of PTSD patients — the region responsible for inhibiting the amygdala. Ketogenic therapy addresses PTSD through three pathways: BHB stimulates BDNF production, promoting hippocampal neurogenesis and volume restoration; ketosis reduces neuroinflammation — chronically elevated in PTSD and a driver of cortisol dysregulation; and stable brain energy supply restores PFC metabolic capacity, re-enabling the top-down inhibitory control over the amygdala that trauma had disabled.

Five stories

Zara — Combat PTSD

Zara, 31, was a veteran with combat PTSD diagnosed after two overseas deployments. She had chronic hypervigilance, nightmares every night, and could not use public transport. Standard EMDR therapy produced partial improvement that stalled. Her VA clinician referred her to a metabolic psychiatry programme that added ketogenic nutrition to her ongoing EMDR. Within three months her sleep improved substantially — the nightmares became less frequent, their content less vivid. The EMDR then progressed where it had previously been blocked. She now uses public transport and works a full-time job.

Marcus — Childhood trauma PTSD

Marcus, 44, had PTSD rooted in severe childhood trauma that had never been adequately treated. He had decades of emotional dysregulation, relationship breakdown, and self-medication with alcohol. When he finally engaged with trauma therapy, his metabolic assessment revealed chronically elevated cortisol, depleted BDNF, and hippocampal volume loss on MRI. Ketogenic nutrition combined with trauma-focused therapy produced changes that therapy alone had never achieved. He describes the metabolic support as giving his brain the rebuilding material the therapy required but could not provide alone.

Rachel — Sexual assault PTSD

Rachel, 27, developed PTSD following sexual assault. She had severe dissociation — the cortisol-driven amnesiac response that prevented her from staying present in therapy sessions. A metabolic intervention reduced her baseline cortisol within six weeks. As the cortisol normalised, her dissociative episodes became less frequent and she could tolerate trauma processing in sessions for the first time. Her therapist described the metabolic preparation as unlocking access to the trauma material that the dissociation had been guarding.

Sean — First-responder PTSD

Sean, 38, was a paramedic with PTSD accumulated over twelve years of critical incident exposure. He had not sought treatment, attributing his symptoms to occupational hazard, until panic attacks began occurring on shift. His inflammatory markers — CRP, IL-6 — were at the high end of normal. He was not clinically inflamed, but his psychiatrist argued this represented a priming state in which his nervous system was operating with minimal reserve. A ketogenic anti-inflammatory diet plus structured sleep hygiene normalised his inflammatory profile. His symptom severity halved over four months without pharmaceutical intervention.

Ada — PTSD with complex comorbidities

Ada, 36, had complex PTSD — prolonged childhood trauma rather than a single incident — with comorbid depression and borderline personality features. Her treatment had been fragmented across years of crisis intervention. A metabolic psychiatrist assessed her and found severe mitochondrial dysfunction markers alongside the expected cortisol dysregulation. The metabolic programme was introduced as a stabilisation phase before resuming trauma therapy. Ada describes the stabilisation as the first time in her adult life that her nervous system felt safe enough to engage with the past.