Evidence
Stress and the HPA axis
A threat activates the hypothalamus, the pituitary and the adrenal glands in sequence.
Cortisol and adrenaline follow. Short bursts help. Chronic activation is linked to
raised blood pressure, impaired immunity and disturbed sleep. Sapolsky's zebra escapes
the lion and recovers; the human keeps the lion in mind.
Evidence
Adverse Childhood Experiences
Felitti and colleagues surveyed over 9,000 adults in a Kaiser Permanente cohort.
Abuse, neglect and household dysfunction in childhood showed a graded, dose response
relation to adult heart disease, lung disease, liver disease and depression. The ACE
score is a population finding, not a personal prognosis.
Evidence
Interoception
The sense of the body's internal state: heartbeat, breath, gut, temperature. Craig
traced its pathway to the insular cortex. Altered interoception appears in anxiety,
depression and eating disorders. Much of shadow work begins as learning to notice
what the body already reports.
Clinical
Functional and psychosomatic disorders
Irritable bowel syndrome, functional neurological disorder, chronic pain without clear
tissue damage. These are real conditions with real disability, diagnosed by positive
criteria, not by exclusion. "Psychosomatic" does not mean imagined. It means
brain and body both take part.
Clinical
Trauma and the body
Van der Kolk's The Body Keeps the Score (2014) made the bodily side of trauma a
public idea. Its core point, that trauma shows in arousal, posture and sensation, is
well supported. Contested: some claims on memory storage and on specific
therapies go past the data.
Clinical
Polyvagal theory
Porges proposed a hierarchy of vagal circuits that govern safety, fight or flight and
shutdown. Therapists use the vocabulary widely. Contested: its physiology and
evolutionary claims are disputed by cardiac and vagal researchers. Treat it as a
clinical metaphor, not established anatomy.
Clinical
Somatic experiencing
Peter Levine's method tracks bodily sensation to discharge stored threat responses. It
is widely practised. Contested: the controlled trials are few and small. Some
results are promising, none is decisive.
Evidence
Slow breathing
Breathing at about six breaths a minute, with an exhalation longer than the inhalation,
lowers arousal for most people. The evidence is modest but real. It is the one tool in
this room that is free, safe and available in the middle of a panic.