3a - PNEI

Question 1

PNEI definition

Answer 1

• PNEI (Psycho-Neuro-Endocrine-Immunology) = interdisciplinary science studying connections &
  communication between psychological, nervous, endocrine & immune systems
• Developed from understanding that mind & body are not separate; health & disease influenced by this
  integrated network

Question 2

Key systems in PNEI

Answer 2

Table

Question 3

Major concepts:
- stress response
- inflammation
- neuroplasticity & mind-body interventions

Answer 3

Stress Response
- Acute vs. chronic stress activate HPA axis → cortisol secretion → modulates immune function.
- Chronic stress = immunosuppression, increased disease vulnerability.

Inflammation
- Chronic low-grade inflammation links mood disorders (ex: depression) to physical illnesses.
- “Sickness behavior” caused by pro-inflammatory cytokines (fatigue, social withdrawal).

Neuroplasticity & Mind-Body Interventions
- Mindfulness, meditation & psychotherapy positively impact brain structure/function & immune markers

Question 4

Clinical implications:
- diagnostic & therapeutic shifts
- disorders with strong PNEI links
- recommended interventions

Answer 4

Diagnostic & Therapeutic Shifts
- Recognizes that psychological conditions can manifest with physical symptoms & vice versa.
- Advocates for holistic & integrative care, including lifestyle interventions, stress reduction & emotional
support

Disorders with Strong PNEI Links:
- Depression, anxiety
- Autoimmune diseases (RA, MS)
- Chronic fatigue syndrome
- Cancer (influence of stress and immunity on progression and prognosis)
- IBS & functional GI disorders

Recommended Interventions:
- Psychotherapy
- Stress management (ex: CBT, relaxation techniques)
- Lifestyle medicine (exercise, sleep, nutrition)
- Complementary approaches: yoga, acupuncture…

Question 5

Scientific foundations

Answer 5

SCIENTIFIC FOUNDATIONS
- Cellular receptors for neurotransmitters and hormones are present on immune cells.
- Bidirectional communication between brain and immune system via:
o Neural pathways (ex: vagus nerve)
o Endocrine signaling
o Cytokines crossing the blood-brain barrier