Summary - Stress and Health
Lecture 1 - Introduction
Evidence-based Medicine
● Scientific evidence and expert opinion as basis for clinical practice
● Evidence levels
○ Clinical observation
○ Observational studies (more reliable if bigger sample)
○ Systematic review of observational studies
○ RCT, systematic review of RCTs
● 5 steps of evidence-based medicine
○ Consensus on constructs
○ Gather evidence
○ Analysis of evidence
○ Results and shortcomings
○ Dissemination
Defining Stress
● Definitions
○ Condition or feeling experienced when a person perceives that demands exceed personal and social resources
the individual is able to mobilize
○ Constellation of events, consisting of a stimulus (stressor) that precipitates a reaction to the brain (stress
perception), that activates physiological fight or flight systems in the body (stress response)
● Shift in stressful events
○ Ancient history
■ Acute physical crisis (e.g. attack by lion; immediate danger)
■ Chronic physical crisis (e.g. malnutrition; over long time)
○ New
■ Psychological crisis
■ Social crisis
■ Prolonged psychological stress
○ -> different kind of stress, not really physical anymore
Stress and Health
● Effect of stress
○ Stress -> health (acute)
○ Stress -> psychological problems -> health
○ Stress -> psychological problems -> behavioral components -> health
■ Behavioral e.g. overeating, alcohol
● Stress does not necessarily always directly affect health
● Stress in clinical practice
○ Makes people sick without having a disease (unnecessary use of healthcare)
○ Increases odds for development of mental and physical health problems
○ Negatively affects
■ Recovery after a disease or injury
■ Effects of medical interventions
■ Patient-physician communication
● If stressed, forgetting more information received
○ ‘Not done’ explanations
■ Patient feeling like not diagnosed correctly, if psychological explanation given
● Homeostasis
○ Body’s ideal level of oxygen, temperature, etc.
○ Sought by brain
○ Stressor can be anything that disrupts homeostasis
○ Stress-response is body’s reaction to reestablish homeostasis
● Stress can be adaptive and disruptive
○ Adaptive : stress is good if
■ Acute
■ Short duration
■ Fast recovery
■ Preparing body for danger signaling danger
○ Disruptive: stress is bad if
■ Chronic
■ Long duration
■ Slow recovery
■ Early onset
■ Preparing body for? / signaling what?
, ○ Transitioning from adaptive to harmful effects of stress
● Positive consequences of exposure to stress
○ Short-term stress: minutes to hours
■ Increase in immunoprotection
■ Enhancement mental and physical performance
○ Chronic stress: prolonged
■ Suppressing auto-immune disease symptoms
● Only helpful short-term!
● Negative consequences of exposure to stress
○ Short-term
■ Emotional level (e.g. negative mood)
■ Cognitive level (e.g. concentration, memory)
■ Behavioral level (e.g. smoking, alcohol)
■ Biological level (e.g. immune, endocrine)
○ Long-term (more indirect)
■ Health / disease
● Development of auto-immune disease, cardiovascular disease, cancer
History of Stress
● Charles Darwin (1809-1892)
○ “Organisms capable of adapting to changing environment will survive”
● Claude Bernard (1813-1878)
○ “Milieu interieur”
○ Inner environment should be stable -> able to cope better
● Walter B. Cannon (1871-1945)
○ “Flight or fight response”
○ About acute stress, body prepares to do so, release of certain hormones
Autonomic Nervous System
● Autonomous -> working on its own
● Subdivision
○ Parasympathetic
■ Restores body to state of calm
■ Digestion
■ Actions not requiring immediate reaction
○ Sympathetic
■ Activates fight flight response
■ Active when we are
CNS and Endocrine System
● Interact with each other
○ CNS
■ Brain
■ Spinal cord
■ Nerves
○ Endocrine system
■ Pituitary gland
■ Thyroid gland
■ Adrenal gland
■ Pancreas
■ Testicles
■ Ovary
, ● Signaling
○ CNS -> sympathetic adrenomedullar system -> hormones (SAM)
■ Increasing adrenaline
○ Hypothalamus -> pituitary -> adrenal gland -> hormones (HPA-axis)
■ Increasing cortisol
■ Few minutes after SAM
● Stress response hormones
○ SAM
■ Epinephrine (adrenaline)
■ Norepinephrine
○ HPA
■ Somewhat later release
■ Starting point: brain
■ Glucocorticoids
● Cortisol, steroids, estrogens, progestins, etc.
○ Additional stress hormone activation
■ Pancreas
● Glucagon (energy during stress)
■ Pituitary
● Prolactin (represses reproduction)
● Vasopressin (increase blood pressure -> heart rate up -> activation body)
■ Pituitary + brain
● Endorphins (blunting pain perception)
● Enkephalins
○ Inhibition of hormonal systems during stress
■ Reproductive hormones (estrogen, testosterone)
■ Growth hormones (insulin)
● Insulin: makes energy store in cells -> less energy available
● Hans Selye (1907-1982)
○ “Every stress leaves an incredible scar, and the organism pays for its survival after a successful situation by
becoming a little older”
○ General Adaptation Syndrome (GAS)
■ Every stressor has three stages
● Alarm stage (initial response)
○ First encounter with stressor
○ Boost of adrenaline, increase in energy
○ Fight or flight
○ Symptoms
■ Energy
● Resistance stage (on-guard)
○ May look like you cope, but body still trying to survive
○ Cortisol
○ Repair
○ Dealing with stress if not possible to repair
○ Symptoms
■ Irritability, frustration, poor concentration, on border to burnout
● Exhaustion stage (low ability)
○ Body giving up on fighting stress, exhaustion, tiredness
○ Symptoms
■ Fatigue, burnout, anxiety, depression
■ Physical consequences possible, damage to body
○ Conclusion GAS
■ Stress is a physiological response only
■ Non-specific response of body to any need or threat
● Reactivity Hypothesis
○ Stressor accompanied by physiological response
○ Response is adaptive
○ Response starts and stops with stressor
Psychologists Perspective on Stress
● J.W. Mason (1975)
○ “Reaction to stress varies between individuals and within individuals (time)’
● Susan R. Burchfield (1979)
○ “Failure to adapt to chronic stress suggests psychological, not physiological exhaustion”
, ● Prolonged activation model
○ Stressor will only affect health when physiological effect is prolonged (e.g. occurring long before stressor or
recovers slowly)
○ Reactivity hypothesis: similar model, but about acute stress
● Michigan Stress Model (Kahn et al., 1964)
● Conclusion psychologists
○ Stress response not purely physiological
○ Not everybody has same stress response
○ Stress response and duration different between and within persons
● Cycle of Stress (Reznick, 1989)
○ Psycho-biological response to stress -> need to focus on both
○ Measuring both psychological and physiological components in 4 phases
■ Resting ground phase
■ Tension phase
■ Response phase
■ Relief phase
○ Measuring frequency, duration, intensity
● Stress response activation
○ Activated by anything that disrupts homeostasis
■ Adaptive
■ Anticipated
● Necessary -> prepares you to combat
● Unnecessary -> prepares you for nothing; anxiety, neurosis
■ Acute (short term)
■ Chronic (long term)
● Differences in stress response
○ Individual differences (response stereotypy)
■ Stress perception
■ Processing
■ Appraisal
■ Coping
■ Genetic makeup
○ Situational differences (situational stereotypy)
■ Situations eliciting different biological responses
● Stressor and stress response
○ Not all stressors produce same stress response
○ Hormonal signature for particular stressor
○ Body sensitivity to stress hormones
○ Psychological context
● Gender differences
○ Fight or flight
■ Male reaction
■ More aggressive
■ SNS, glucocorticoids
○ Tend and befriend
■ Female reaction
■ Taking care
■ Seeking social affiliation
■ Oxytocin
● Damage of the stress response
○ Inability to turn it on -> disease (body cannot signal danger; no fear cars when crossing street)
○ Inability to turn it off -> disease (chronic stress)
○ Inability to turn it on/off completely -> disease (stress unrelated to stressor, no turning off after passed)
● Historical perspectives
○ Norwegian experiment (“Gating mechanism”)
■ 11 consecutive days of jumping from 12m height
■ Increase physiological response Day 1-4 (peak day 4)
Lecture 1 - Introduction
Evidence-based Medicine
● Scientific evidence and expert opinion as basis for clinical practice
● Evidence levels
○ Clinical observation
○ Observational studies (more reliable if bigger sample)
○ Systematic review of observational studies
○ RCT, systematic review of RCTs
● 5 steps of evidence-based medicine
○ Consensus on constructs
○ Gather evidence
○ Analysis of evidence
○ Results and shortcomings
○ Dissemination
Defining Stress
● Definitions
○ Condition or feeling experienced when a person perceives that demands exceed personal and social resources
the individual is able to mobilize
○ Constellation of events, consisting of a stimulus (stressor) that precipitates a reaction to the brain (stress
perception), that activates physiological fight or flight systems in the body (stress response)
● Shift in stressful events
○ Ancient history
■ Acute physical crisis (e.g. attack by lion; immediate danger)
■ Chronic physical crisis (e.g. malnutrition; over long time)
○ New
■ Psychological crisis
■ Social crisis
■ Prolonged psychological stress
○ -> different kind of stress, not really physical anymore
Stress and Health
● Effect of stress
○ Stress -> health (acute)
○ Stress -> psychological problems -> health
○ Stress -> psychological problems -> behavioral components -> health
■ Behavioral e.g. overeating, alcohol
● Stress does not necessarily always directly affect health
● Stress in clinical practice
○ Makes people sick without having a disease (unnecessary use of healthcare)
○ Increases odds for development of mental and physical health problems
○ Negatively affects
■ Recovery after a disease or injury
■ Effects of medical interventions
■ Patient-physician communication
● If stressed, forgetting more information received
○ ‘Not done’ explanations
■ Patient feeling like not diagnosed correctly, if psychological explanation given
● Homeostasis
○ Body’s ideal level of oxygen, temperature, etc.
○ Sought by brain
○ Stressor can be anything that disrupts homeostasis
○ Stress-response is body’s reaction to reestablish homeostasis
● Stress can be adaptive and disruptive
○ Adaptive : stress is good if
■ Acute
■ Short duration
■ Fast recovery
■ Preparing body for danger signaling danger
○ Disruptive: stress is bad if
■ Chronic
■ Long duration
■ Slow recovery
■ Early onset
■ Preparing body for? / signaling what?
, ○ Transitioning from adaptive to harmful effects of stress
● Positive consequences of exposure to stress
○ Short-term stress: minutes to hours
■ Increase in immunoprotection
■ Enhancement mental and physical performance
○ Chronic stress: prolonged
■ Suppressing auto-immune disease symptoms
● Only helpful short-term!
● Negative consequences of exposure to stress
○ Short-term
■ Emotional level (e.g. negative mood)
■ Cognitive level (e.g. concentration, memory)
■ Behavioral level (e.g. smoking, alcohol)
■ Biological level (e.g. immune, endocrine)
○ Long-term (more indirect)
■ Health / disease
● Development of auto-immune disease, cardiovascular disease, cancer
History of Stress
● Charles Darwin (1809-1892)
○ “Organisms capable of adapting to changing environment will survive”
● Claude Bernard (1813-1878)
○ “Milieu interieur”
○ Inner environment should be stable -> able to cope better
● Walter B. Cannon (1871-1945)
○ “Flight or fight response”
○ About acute stress, body prepares to do so, release of certain hormones
Autonomic Nervous System
● Autonomous -> working on its own
● Subdivision
○ Parasympathetic
■ Restores body to state of calm
■ Digestion
■ Actions not requiring immediate reaction
○ Sympathetic
■ Activates fight flight response
■ Active when we are
CNS and Endocrine System
● Interact with each other
○ CNS
■ Brain
■ Spinal cord
■ Nerves
○ Endocrine system
■ Pituitary gland
■ Thyroid gland
■ Adrenal gland
■ Pancreas
■ Testicles
■ Ovary
, ● Signaling
○ CNS -> sympathetic adrenomedullar system -> hormones (SAM)
■ Increasing adrenaline
○ Hypothalamus -> pituitary -> adrenal gland -> hormones (HPA-axis)
■ Increasing cortisol
■ Few minutes after SAM
● Stress response hormones
○ SAM
■ Epinephrine (adrenaline)
■ Norepinephrine
○ HPA
■ Somewhat later release
■ Starting point: brain
■ Glucocorticoids
● Cortisol, steroids, estrogens, progestins, etc.
○ Additional stress hormone activation
■ Pancreas
● Glucagon (energy during stress)
■ Pituitary
● Prolactin (represses reproduction)
● Vasopressin (increase blood pressure -> heart rate up -> activation body)
■ Pituitary + brain
● Endorphins (blunting pain perception)
● Enkephalins
○ Inhibition of hormonal systems during stress
■ Reproductive hormones (estrogen, testosterone)
■ Growth hormones (insulin)
● Insulin: makes energy store in cells -> less energy available
● Hans Selye (1907-1982)
○ “Every stress leaves an incredible scar, and the organism pays for its survival after a successful situation by
becoming a little older”
○ General Adaptation Syndrome (GAS)
■ Every stressor has three stages
● Alarm stage (initial response)
○ First encounter with stressor
○ Boost of adrenaline, increase in energy
○ Fight or flight
○ Symptoms
■ Energy
● Resistance stage (on-guard)
○ May look like you cope, but body still trying to survive
○ Cortisol
○ Repair
○ Dealing with stress if not possible to repair
○ Symptoms
■ Irritability, frustration, poor concentration, on border to burnout
● Exhaustion stage (low ability)
○ Body giving up on fighting stress, exhaustion, tiredness
○ Symptoms
■ Fatigue, burnout, anxiety, depression
■ Physical consequences possible, damage to body
○ Conclusion GAS
■ Stress is a physiological response only
■ Non-specific response of body to any need or threat
● Reactivity Hypothesis
○ Stressor accompanied by physiological response
○ Response is adaptive
○ Response starts and stops with stressor
Psychologists Perspective on Stress
● J.W. Mason (1975)
○ “Reaction to stress varies between individuals and within individuals (time)’
● Susan R. Burchfield (1979)
○ “Failure to adapt to chronic stress suggests psychological, not physiological exhaustion”
, ● Prolonged activation model
○ Stressor will only affect health when physiological effect is prolonged (e.g. occurring long before stressor or
recovers slowly)
○ Reactivity hypothesis: similar model, but about acute stress
● Michigan Stress Model (Kahn et al., 1964)
● Conclusion psychologists
○ Stress response not purely physiological
○ Not everybody has same stress response
○ Stress response and duration different between and within persons
● Cycle of Stress (Reznick, 1989)
○ Psycho-biological response to stress -> need to focus on both
○ Measuring both psychological and physiological components in 4 phases
■ Resting ground phase
■ Tension phase
■ Response phase
■ Relief phase
○ Measuring frequency, duration, intensity
● Stress response activation
○ Activated by anything that disrupts homeostasis
■ Adaptive
■ Anticipated
● Necessary -> prepares you to combat
● Unnecessary -> prepares you for nothing; anxiety, neurosis
■ Acute (short term)
■ Chronic (long term)
● Differences in stress response
○ Individual differences (response stereotypy)
■ Stress perception
■ Processing
■ Appraisal
■ Coping
■ Genetic makeup
○ Situational differences (situational stereotypy)
■ Situations eliciting different biological responses
● Stressor and stress response
○ Not all stressors produce same stress response
○ Hormonal signature for particular stressor
○ Body sensitivity to stress hormones
○ Psychological context
● Gender differences
○ Fight or flight
■ Male reaction
■ More aggressive
■ SNS, glucocorticoids
○ Tend and befriend
■ Female reaction
■ Taking care
■ Seeking social affiliation
■ Oxytocin
● Damage of the stress response
○ Inability to turn it on -> disease (body cannot signal danger; no fear cars when crossing street)
○ Inability to turn it off -> disease (chronic stress)
○ Inability to turn it on/off completely -> disease (stress unrelated to stressor, no turning off after passed)
● Historical perspectives
○ Norwegian experiment (“Gating mechanism”)
■ 11 consecutive days of jumping from 12m height
■ Increase physiological response Day 1-4 (peak day 4)
