Stress and Stress Response PDF

Week 3.3 _ Stress & The Stress Response Homeostasis - Physiology  All organisms maintain a complex dynamic equilibrium, or homeostasis (“stability through constancy”)  Stressors is something that upsets that balance.  Stress represented a deviation from some norm or steady state. ◦ Postprandial /...

Week 3.3 _ Stress & The Stress Response Homeostasis - Physiology  All organisms maintain a complex dynamic equilibrium, or homeostasis (“stability through constancy”)  Stressors is something that upsets that balance.  Stress represented a deviation from some norm or steady state. ◦ Postprandial /Glucose levels ◦ Body temperature Stress & Health - History  The influence that stress can have on an individual’s health has been cited by healers for centuries.  In ancient India, texts were found describing the relationship between “moods and disease”.  In 200 AD, Galen stated that “melancholic” women are more prone to breast cancer than “sanguine” women. Stress & Health  Even Louis Pasteur, the scientist who helped develop the germ theory of disease, showed that stress could alter an organism’s resistance to disease. Stress & Health  In 1878 Pasteur performed an experiment in which chicken, normally a species not affected by anthrax, would develop the disease if the chickens were subjected to significant stress. The Study of Stress Walter Cannon  “Fight or Flight” response  Physical or psychological danger  System-wide arousal of the body  Sympathetic nervous system  Adrenal glands  Energy mobilization  “wild state readiness for fight or run!” Stress Response  Changes are adaptive for brief periods of physical exertion Hans Selye Hans Selye  Selye subjected rats to various stressors such as very cold or hot temperatures and loud noises.  These stressors where also chronic in nature, which means he exposed the rats to these stressors for long periods of time. General Adaptation Syndrome  What Selye found was that under such conditions the rats were forced to adapt to their environment, a process known as general adaptation syndrome (GAS). General Adaptation Syndrome  There are three main stages associated with the general adaptation syndrome: the alarm reaction, the stage of resistance and the stage of exhaustion. The Alarm Reaction  Increased state of arousal  Heart rate increases  Rate of respiration increases  Muscles tense up in preparation to deal with the stressor (either escape from it or fight it). The Stage Of Resistance  Chronic exposure to a stressor results in the body “getting used to” the stressor and is characterized by a reduced level of arousal.  Even though the conditions may continue to be stressful, the rat learns to live in its new environment and is capable of reproducing and learning new things The Stage Of Exhaustion  Prolonged exposure to a stressor (chronic stress) eventually takes its toll, and the rat dies a premature death.  The stage of exhaustion occurs when the normal physiology cannot compensate as well and soon disease states develop and the animal dies prematurely.  “Adrenaline/Cortisol Poisoning” Fight or Flight  Rapid, stereotypical response  Short term crisis – adaptive , survival  Provides immediate energy  Increases delivery of nutrients  Turns off slow of “nonessential” process  Digestion Immediate Energy Breakdown of glycogen  Glucose released from liver  Free fatty acids released from adipose   Increase in glucose and fatty acids in the blood Delivery of Nutrients Increase in heart rate  Increase in blood pressure  Increase in respiration rate  Turns Off Non-Essential Processes  Inhibition of processes associated with growth, repair, long term building Inhibition of digestion  Inhibition of reproduction  Decrease in growth hormone  Decrease in sex hormones levels  Neurological / Hematological  Initial boost in immune function  Increase in clotting factors in blood  Stress induced analgesia – blunt pain  Increases blood flow to brain  Increases arousal (RAS)  Creates focus / tunnel vision  “Flashbulb” memory  Although the autonomic stress response is often characterized as the fight-or-flight reflex, it is rare that everyday stress requires either fighting or fleeing. Chronic Stress  Chronic stress response is MALADAPTIVE to long term survival. Leads to/ contributes to disease  Elevation of Glucose & FFA ◦ Metabolic syndromes: obesity, hyperlipidemia, ◦ Type 2 diabetes  Increased CV function ◦ Primary hypertension ◦ Increased risk of MI & CVA ◦ Heart rhythm irregularities Chronic Stress  Inhibition Of Growth & Repair ◦ Immunosupression ◦ Poor wound healing ◦ Infertility  Nervous System Changes ◦ ◦ ◦ ◦ Impaired memory & sleep disturbances Neuronal atrophy Anxiety, Depression PTSD  intense, disturbing thoughts and feelings  flashbacks or nightmares  may feel detached or estranged from other people Paul MacLean – Triune Brain Triune Brain Model  “Reptilian” – Basic reflexive functions; Keep the organism alive  “Mammalian” – Limbic system – emotions (Rage / Fear )  “Human” - Cognition, Abstract thought, Theory of mind, Memories Psychological & Psychosocial Stress Psychological Stress  A perceptual phenomenon arising from a comparison between the demand on the person and his ability to cope.  An imbalance gives rise to the experience of stress and the stress response. Psychological Stress  Subjective nature of stress and its psychological dimension  Events viewed as challenging or threatening ◦ Thoughts ◦ Memories ◦ Learned / Experiences ◦ Conditioned Response Sources of Psychological Stress  Frustration : any situation is where a goal is thwarted, a helplessness stress  Change : welcome (+ ) unwelcome (-)  Pressure : expectations/demands that one behave in a certain way.  Pressure can be imposed by self or others  Conflict : incompatible motives, impulses, values, or beliefs a decision stress The Holmes-Rahe Stress Inventory 150 p o in t s o r le s s | a re la t ive ly lo w a m o u n t o f life c h a n g e a n d a lo w s u s c e p t ib ilit y t o s t re s s -in d u c e d h e a lt h b re a kd o w n 150 t o 30 0 p o in t s | 50 % c h a n c e o f h e a lt h b re a kd o w n in t h e n e xt 2 ye a rs 30 0 p o in t s o r m o re | 8 0 % c h a n c e o f h e a lt h b re a kd o w n in t h e n e xt 2 ye a rs , a c c o rd in g t o t h e Ho lm e s -Ra h e s t a t is t ic a l p re d ic t io n m o d e l https://www.stress.org/holmes-rahe-stress-inventory Physiology of the Stress Response  Autonomic Nervous System  “Fight or Flight “ response  HPA – Axis ◦ Hypothalamus ◦ Pituitary ◦ Adrenal glands Autonomic Nervous System  Visceral Nervous system ◦ Regulates the actions of glands, hollow organs, blood vessels and heart muscle.  Actions are reflexive  (without conscious awareness)   Sympathetic Nervous System  Fight or Flight   Mobilize energy / Rapid / Emergencies Norepinephrine / epinephrine Parasympathetic Nervous System  “Rest and Digest” - Calm vegetative function    Storage of energy – restore homeostasis Recovery – Neuro-restorative - Slower, time consuming Acetylcholine Stress Hormones: Cortisol  “Glucocorticoid”  Increase glucose levels  aa  Glucose  Inhibit protein synthesis  Released during “stress”  Influences brain ◦ Thought, Mood, Behavior Cortex Limbic System Hypothalamus CRH Pituitary ACTH Adrenals Adrenaline Cortisol Glucocorticoid-Induced Insulin Resistance  Chronic glucocorticoid (GC) exposure in humans can result in whole-body insulin resistance and obesity.  Metabolic syndrome is linked with insulin resistance, cardiovascular risk, and decreased survival.  Subtle forms of endogenous GC excess are seen in the setting of chronic stress (overactivation of the hypothalamic-pituitary-adrenal (HPA) axis) leading to increased production of adrenal cortisol. The study of GC-induced obesity  Common obesity is believed to be associated with abnormalities in the HPA axis  Presence of increased local production of GCs in the adipose tissue, alterations in cortisol circadian rhythm, and enhanced susceptibility of the HPA axis to be activated  Chronic GC exposure promotes insulin resistance, focusing in particular on the effects on adipose tissue function and lipid metabolism. Robert Sapolsky Stress & the Primate Brain The primate brain is hardwired to perceive experiences Then to identify them as negative, neutral, or positive, and to react to them. Stress Signatures  Individuals have different sensitivity levels to stress. Genetics  Temperament / Personality  History  Education  Culture  Cognition  Coping skills  Learned behavior  Threat vs. Challenge  Threat is an unpleasant state of mind that may seriously block mental operations and impair functioning  Challenge is exhilarating and associated with expansive, often outstanding performance  Eustress was the good kind of stress because it was associated, presumably, with positive feelings and healthy bodily states.  Distress was the bad kind, associated with negative feelings and disturbed bodily states. Physiological Effects of Chronic Stress Stress & the CV System  Primary Hypertension  Left ventricular hypertrophy  Epithelial damage at bifurcations  Inflammation  Atherosclerosis  Thrombosis & emboli Stress & Metabolism Stress & Immune system  The Metabolic Syndrome:  Glucocorticoids (cortisol)  Hyperphagia   Type 2 Diabetes Increase susceptibility to infections such as cold and flu  Immuno- surveillance  Impairs wound healing   Hyperlipidemia Obesity Chronic Stress & CNS  Chronic pain  Poor concentration  Learning & memory  Memory lapses Sleep  Confusion  Panic attacks  Difficulty making decisions   Frontal Cortex (?) ◦ Judgement ◦ Impulse control Behavioral / Interpersonal Symptoms Appetite changes / Eating disorders  Increased smoking  Hostility  Increased alcohol intake  Impatience  Restlessness  Depression  Fidgeting / Nail biting  Tearfulness  Procrastination  Irritability  Diminished productivity /  Withdrawal Absenteeism  Social avoidance  Accidents  Marital/family disharmony  Hypochondria  Coping Coping  In 1984, Lazarus and Folkman defined the coping process. ◦ The effectiveness of coping determines to some extent the body’s response to stressors and whether the physiological stress response will continue or diminish.  An individual can learn to develop skills to increase the ability to cope. Unhealthy coping Constructive coping  Aggression  Assertive behavior  Passivity  Stress management ◦ “learned helplessness”  Healthy lifestyle  Passive aggressive behavior  Realistic problem-solving  Addiction  Cognitive restructuring  Denial, fantasy, intellectualization, undoing, overcompensating Communication Styles  Assertive: Direct communication  Aggressive: Fear, threats, intimidation & hostility  Manipulative: guilt, emotional appeal  Passive: going along, not making waves  Passive aggressive: Spiteful, hidden resentment, teaching someone a “lesson” Exercise Dr Kenneth Cooper Dr Kenneth Cooper  “According to the Gallup Poll, 24 percent of American adults exercised regularly in 1961, and 50 percent after 1968.  The peak was 59 percent in 1984, dropping off to 51 percent last September.” Sleep Stages of Sleep Nutrition Social Support  “Social Support and Resilience to Stress” ◦ From Neurobiology to Clinical Practice Numerous studies indicate social support is essential for maintaining physical and psychological health. The harmful consequences of poor social support and the protective effects of good social support in mental illness have been well documented. Social support may moderate genetic and environmental vulnerabilities and confer resilience to stress, possibly via its effects on the hypothalamic-pituitary-adrenocortical (HPA) system, the noradrenergic system, and central oxytocin pathways. The Hardy Personality The Hardy Personality  Hypothesized that hardiness—commitment, control, and challenge—functions to decrease the effect of stressful life events to producing illness symptoms. a) A sense of control over ones life  b) A feeling of being committed to work, family or hobby  c) A sense of challenge in which change is viewed as an opportunity to develop  Hardiness and health: A prospective study. Kobasa, Suzanne C.; Maddi, Salvatore R.; Kahn, Stephen Journal of Personality and Social Psychology, Vol 42(1), Jan 1982, 168-177 The “Hardy” personality Certain personalities appear to be more resistant to stress. These qualities include:  a) A sense of control over ones life  b) A feeling of being committed to work, family or hobby  c) A sense of challenge in which change is viewed as an opportunity to develop  Meditation / Mindfulness Herbert Benson Tum-mo ‘inner fire’ http://www.youtube.com/watch?v=5Arr4C52grQ&feature=related A Buddhist monk has his vital signs measured as he prepares to enter an advanced state of meditation in Normandy, France. During meditation, the monk's body produces enough heat to dry cold, wet sheets put over his shoulders in a frigid room Daniel Goleman Mindfulness + Prefrontal lobe Jon Kabat-Zinn - Middle Prefrontal area  Body Regulation  Attuned Communication  Emotional Balance  Fear Modulation  Response-Flexibility  Insight  Empathy  Decision making Research  Mindfulness practice leads to increases in regional brain gray matter density  Psychiatry Research: Neuroimaging, Volumes 191 - 194 (2011), p. 36 - 43  Britta K. Hölzela,, James Carmodyc, Mark Vangela, Christina Congletona, Sita M. Yerramsettia,Tim Garda,b, Sara W. Lazara Research  Mindfulness-Based Stress Reduction (MBSR)  Anatomical magnetic resonance(MR) images from 16 healthy, meditationnaïve participants were obtained before and after they underwent the 8-week program.  The results suggest that participation in MBSR is associated with changes in gray matter concentration in brain regions involved in learning and memory processes, emotion regulation, selfreferential processing, and perspective taking. Allostasis