Psychoneuroimmunology Flashcards
Define psychoneuroimmunology (3)
’Psychoneuroimmunology (PNI) is the study of the interaction between psychological processes, the nervous system and the immune system of the human body
‘-Psycho-‘ means thoughts and emotions
‘-neuro-‘ means that the physical brain is involved
‘-immunology’ explains how your immune system protects you from illness
PNI takes an interdisciplinary approach, incorporatingpsychology,neuroscience,immunology,physiology,genetics,pharmacology,molecular biology,psychiatry,behavioural medicine,infectious diseases,endocrinology, andrheumatology
PNI more info (4)
Psychoneuroendoimmunology: ‘-endo-‘ brings in the endocrine system
PNI researchers study how your emotions and thoughts impact your brain, hormones, and nervous system and also your immune system’s ability to protect you -> all sickness is organic
It can also work the other way - changes in the immune and endocrine systems create changes in your nervous system which lead to changes in your emotions.
Stress causes the nervous system to activate the immune system. The two systems communicate via the endocrine system
What’s the point of PNI research? (6)
Immune cells in the blood and spleen produce pro-inflammatory (IL-1,-6, TNFα, interferon gamma (INF)) and anti-inflammatory (IL-4,-10,- 13, TGFβ) cytokines.
We now know astrocytes, microglia and neurons in the brain also produce these immuno-transmitters.
In depression, there is an increase in pro-inflammatory cytokines in the blood and brain.
Symptoms such as depression and anxiety appear to stimulate proinflammatory cytokines such as IL-6. We also know that depressed patients have a decreased number of peripheral T cells, also impacts CVS health, influencing platelet activation, influences blood vessels inflammation)
Similar changes occur after chronic stress and following brain lesions resulting from a stroke (lesions usually cortex = reduction in natural killer cell activity, T cell prolif.)
The macrophage theory of depression, proposed by Smith in 1991 -> increase in proinflamm cytokines + reduction of anti inflammatory cytokines = reflection of chronic low grade inflam processes => depression symptoms
What is Psychomatic disease? explain with an example (3)
It is a disease which involves both mind and body. Some physical diseases are thought to be particularly prone to being made worse by mental factors eg stress and anxiety.
a physical disease caused or made worse by psychological factors , also when psychological factors cause physical symptoms where there may not be a specific physical etiology eg chest pain because of stress (but not physical indication as to why there is pain in physical exam)
Therefore your mental state can affect how bad a physical disease is at any given time
What was found about the therapeutic use of IFN alpha for hepatitis or MS? (2)
it’s associated with depressive symptoms in a substantial minority of otherwise non-depressed patients.
Psychosocial issues, while often seen as separate and distinct from biologic concerns, directly influence multiple body systems and impact the health and disease of the individual
List some somatic conditions with behavioural/psychiatric manifestations (7)
The presentation and association of somatic conditions with behavioural and psychiatric manifestations highlight the interconnectedness between physical and mental health
Epilepsy = Nutritional deficies (B12, D,A, Zinc)
Dementia = Endocrinopathies (Thyroid anomalies, hypoglycemia, Addison’s, Cushing’s)
Delirium = Infections (HIV, TB, Prion disease, encephalitis, HSV, syphilis)
CVA = MS
structural brain abnormalities = Huntingdon’s
Wilson disease = SLE
Parkinson’s = Neoplastic disease
what are some factors that can influence PNI? (5)
drugs
genetic mutations
stress
environmental exposure
gut microbiota
Is the presence of disease agents sufficient for disease manifestation? (1)
no! you need to look at how psychological, physical and emotional factors can influence immunity + disease
How could psychological factors influence immunity and disease? - flowchart (5)
1)Psychological characteristic or state
2) = 3 different responses: CNS innervations, Hormonal response, behavioural change
3) = Immune change (constantly altering)
4) Disease susceptibility (stressful events, coping, smoking, poor dietary habits, poor sleeping)
What are the studies surrounding medical students and stress? (3)
Medical students
blood test + saliva swabs taken Soon after vacation and soon after exam
= Decreased activity of immune response (NK activity, lymphocyte production of cytokines and lymphocyte proliferation, increased production of herpes)
What is the influence of psychological factors in immune-mediated disease? (7)
Affect: depressive disorders -> specific behaviour = increased drink, smoke, poor sleep, poor exercise
= direct effect on immune system (nk cells, t cells etc)
but also these effect immune system:
- Mood states: anxiety
-Personality: pessimistic, power motivation, repression/denial (HIV)
-Interpersonal relationships: support-induced changes in immune function?
Stressful emotions also reduce the numbers and effectiveness of immune system cells, including the inflammation response which is part of your non-specific protection.
It can also reduce the t cells that directly attack invaders and the Natural Killer (NK) t-cells that rid you of cancers.
It can also reduce the macrophages that also attack directly the cells and processes, including cytokines, that fuel chronic inflammation – which therefore pose a risk factor for cardiovascular disease and cancer
Explain stressors and the stress response (4)
Stressors and the stress response are distinct concepts
Stressors: most investigations examine stress by studying stressors: events which most people would find stressful. -> give rise to behavioural, physiological + psychological stress response
Stressful emotions also reduce the numbers and effectiveness of immune system cells, including the inflammation response(non-specific protection)
data= people undergoing divorce, bereavement, family caregiving, academic examinations, daily hassles, and financial hardship report greater distress than those not experiencing these stressors.
Consistent w/ theory, data also show that individuals vary in their subjective reactions to stress, and this variation is often based on individual differences in personality, coping, self efficacy, and social characteristics
Illustrate the stress + stressor flowchart (5)
1) stressor (individual differences eg personality experience alter how stress is perceived)
2) psychological stress response: cognitive appraisal, behaviour change, emotional distress
3) physiological stress response: CNS/endocrine (HPA/SAM axes)
4) Immune response
5) disease (chronic pain, ANS related disorder + neurological syndrome table)
Can stress reduction mediate the body’s immune response? (3)
Students whom were taught relaxation training had a significant increase in NK cell activity compared to students who had not received the training.
Furthermore, the students that had not received the training had an increase in infectious illness symptoms around exam time.
Other studies have shown decreased inflammatory responses with relaxation interventions as well as promotion of genes associated with DNA stability, improved BP, improved attention and problem solving.
What is a consequence of chronic inflammation? (4)
The lack of adaptation to stress underlies most major psychiatric disorders.
A possible consequence of the chronic inflammation is an increase in apoptosis leading to neurodegenerative changes in the brain. There is evidence that such changes occur in both depression and schizophrenia.
The inflammatory changes shown to occur in major depression are qualitatively similar to those reported in patients with Alzheimer’s disease. This has led to the suggestion that chronic depression can predispose patients to dementia in later life.
-figure summarises the immune/endocrine cascades that may form the basis for the progression from chronic depression to dementia.
Summary 1 (6)
PNI studies the connection between psychological processes and the nervous and immune system.
The brain, the HPA axis and immune systems are closely inter-related.
Psychological factors can influence immune-mediated disease
Stress and emotional states significantly affect immune function and can precipitate physical as well as causing psychological changes.
Cytokines play a key role as immuno-transmitters and co-ordinate the activity of the endocrine, immune and neurotransmitter systems.
Chronic inflammation is linked to a number of diseases, including autoimmune diseases and neurodegeneration
Define stress + the 3 behavioural responses (3)
- Nonspecific response of the body to any demand made upon it
- Events that are interpreted as threatening to an individual and which elicit physiological and behavioural responses
1)alarm (high energy)
2) resistance (alertness + healing)
3) exhaustion (low energy)
What is an individual’s reaction to stress is dependent on? (7)
- type of stress
-chronicity of the stress - genetic predisposition
- health status
- psychological factors
- coping strategies
- interplay of all them
What are the effects of stress on health and disease dependent on? (3)
Recent research demonstrates that stress resilience is biologically mediated but can be altered through non-biological interventions.
(Nature vs Nurture) Psychological distress arises when a person perceives that imposed demands have exceeded their own personal ability to cope with them.
Not only is the type of stressor important to the overall response of the neuroendocrine system on the body, but so is the individual’s perception of and reaction to the stressor
Quickly explain the HPA (3)
Hypothalamic-Pituitary-Adrenal Axis
The HPA axis is modulated by the autonomic nervous system and the HPA axis is also stimulated in the process of inflammation
It is central to the physiologic response to stress
What are the effects of Cortisol, ACTH and CRH on CNS? (5)
When activated Cortisol, ACTH and CRH are released =
* Arousal
* Sensory processing abnormalities
* Increase in perceived pain
* Sleep disturbances
* Memory issues
What are some effects of chronically elevated cortisol (chronic inflam)? (5)
-Hyperglycaemia
-Increased visceral adipose tissue
-Elevated BP
-Decreased bone density
-Increased lipids
What is the relationship between stress and nervous system? (7)
-Stress impacts the immune, nervous and endocrine systems
- Main components of the HPA and sympatheticadrenalmedullary (SAM) axes
-Symp (ANS) innervates lymph organs and tissues.
- can change blood flow/supply to lymphoid tissue.
-Immune cells have receptors for neurotransmitters and hormones.
-Neuropeptides are present on the cell walls in the CNS + in the immune system.
-Cytokines made by the immune cells eg macrophages + mast cells, can directly act on the nervous system.
- R’s expressed in the CNS + PNS
FIGHT + FLY > rest + digest = hypertension, CVS diseases, obesity
Quick summary of Catecholamines (4)
eg Adrenaline, Noradrenaline
- Produced by adrenal gland + postsynaptic sympathetic neurons in SMA axis
- Act on adrenergic receptors
- Response to acute stressors
- Promotes production of pro-inflammatory cytokines
