Health Psychology: Stress Theories PDF

Health psychology Stress theories Definition of stress ==================== - Term influenced by **physics** : force on a solid body caused by an external body, load - **3 different perspectives** : reaction, source of stress, relationship between the two : stress theories - The a...

Health psychology Stress theories Definition of stress ==================== - Term influenced by **physics** : force on a solid body caused by an external body, load - **3 different perspectives** : reaction, source of stress, relationship between the two : stress theories - The ancient Greeks already theorized how stress and and ways of coping with stress can influence health and illness Stress theories --------------- - Stress = reaction to events / specific stimuli - Reaction-oriented theories (ex. Cannon, Seyle) **\ ** - Stress = source of stress (specific events) - Stimulus-oriented theories (ex. Holmes & Rahe) - Stress = relationship between stimuli and reaction - Transactional models of stress Reaction-oriented and psychophysiological stress theories --------------------------------------------------------- - Stress as a physical reaction pattern to stressful events - 2 endogenous regulatory systems that release hormones and transmitters when activated : \- Sympathetic adrenomedullary system \- Hypothalamic-pituitary-Adrenocortical system Psychobiological stress systems ------------------------------- Reaction-oriented and psychophysiological stress theories --------------------------------------------------------- **Cannon : "fight or flight response"** \- strain on organism is related to increased activity of the adrenal medulla -\> release of epinephrine and norepinephrine (Adrenaline et Noradrenaline) -\> releasing energy for **fight or flight** response -\> affects cardiovascular system (increased blood circulation) Theory of **homeostasis** -\> if there is a big deviance from target value, homeostasis is to be restored (ex: fever, glucose) \- Adrenaline and noradrenaline are very important to prepare the body. All the energy goes in fighting or flying, running away fast \- All the energy in the body is focused in the preparation for the fight **Seyle** - S**tress as an unspecific reaction** of the organism to different forms of stressors / source of stress - Triggered and controlled by the release of cortisol - Seyle's medical training : observed how many patients with different illnesses and injuries showed similar to identical symptom patterns - Research with rats : they reactes similarly to a wide variety of stimuli (heat, physical exertion, deprivation) - Seyle is often referred to as the "father of stress" - ACTH : prepares the body to resist the stress - Release of cortisol in the blood : beginning of the 2nd stage - 2: parasympathetic system is blocked ( ex : digestion) - 3 : exhaustion : the body cannot without limit provide the energy to fight / rat experiment : can even cause death Une image contenant texte, capture d'écran, Police Description générée automatiquement -------------------------------------------------------------------------------------- Stimulus-oriented stress theories ================================= - How life events can impact - Family of stress models in which the focus in less on the reaction and **more on the stimulus** (stressful event) **=** on the situation we are facing = only look at the source of stress **[Types of stress]** - Physical stressors : *heat, noise, cold* - Social stressors : *worries about a friend, interpersonal conflits* - Economic stressors : *financial problems, unstable working conditions* - Ecological stressors : *air pollution, negative living conditions* - Occupational stressors *: time pressure, monotony* Forms of stress according to dimensions of **intensity, duration and impact** ( Bodenmann et Gmelch)  - intensity :macro (major) or micro - duration : acute or chronic - impact : personal or universal \- Ex : hectic workplace : it concerns everyone there and everyday ( more people are affected) \- Might not everyone will have an equal stress response - **Life events theory** ( Holmes et Rahe) Ex : marriage is positive but can be stressful, even if they're looking forward to - The degree of social reorientation is crucial ! Social readjusment scale ======================== - Rank of life events , a list of 43 stressful life events that can contribute to illness. **Daily hassles (Kanner)** - Small everyday difficulties (= chronic minor events ) are significant for stressful experience = minor stressful events everyday are also affecting people's health as much as major events Une image contenant texte, capture d'écran, Police Description générée automatiquement Transactional models of stress ( Lazarus) ========================================= - with the environment ( the stimuli ) "Psychological stress refers to a relationship with the environment that is evaluated by the individual as significant in terms of their well-being, but at the same time places demands on the individual that strain or overwhelm their ability to cope "( Lazarus) - Objectively identical stimulus constellations can lead to different stress reactions -\> due to differences in individuals' evaluation processes = The exact same stressors can be evaluated differently by different people : different reactions to this potential stressor - **Dynamic model of stress** : interaction of person and environment - -   -   - -   - - Demands and resources can be external - Ex. internal resource : optimism, resilience, being outgoing - How we evaluate a given situation - If we don't perceive a situation relevant : we don't need to think about our resources  - Emotions : we would have fear if there is a threat - Challenge : increase resource, potentiel gains (learn sth new) Stress is not necessarily sth negative ( eustress = positive stress) - 2 people have different demands in a situation ( demand might be higher for an introvert in a situation) they face the situation differently Has to pay the bills for the family Demand just for him Example : losing a job resources education, might be easier to find a new job, he's optimistic When demands are higher than resources : we perceive stress - Depends on how we cope : might perceive differently - We can think about our resources to cope with stress ( meditation, yoga) / it helps to deal with a situation to see the specific demands and resources of a client - This model explains why the exact same situation can be more/less stressful for everyone Une image contenant texte, capture d'écran, Police, nombre Description générée automatiquement Mind-Body-Interaction ===================== - Psychological factors can have a direct impact on somatic processes - Bodily stress system = highly complex physiological network - Continuous maintenance and restoration of balanced conditions in the organism (equilibrium) - Neuroendocrine stress response (HPA-axis, Sympathetic adrenomedullary system) - Stress and the immune system  - HPA-axis : starts hypothalamus, releases more CRH, stimulate ACTH - Cortisol release in the adrenal cortex is important to shut down the reaction = negative feedback ( in green ) - Limbic system : also important to stop the reaction Epinephrine and the sympathetic adrenomedullary system ====================================================== - Epinephrine : adrenaline, noradrenaline - Fight-flight-response : - Adaptative physical change (Cannon, 1932) - Increase in heart rate, respiration, blood pressure - Vasoconstriction (contraction) of the blood vessels (except striated muscles) - Inhibition of gastrointestinal activity (parasympathetic nervous system ↓) - Release of glucose from the liver - Activation and redirection of energy in the form of oxygen and nutrients - Increase of attention on threat -\> more successful escape or attack reaction Psychosocial factors (ex. Perceived social support) have an impact on hormonal and physiological responses Negative feedback loops HPA-axis ================================ Une image contenant texte, capture d'écran, diagramme, Police Description générée automatiquement  Cortisol : the end product of the HPA-axis ========================================== - "marker of stress", measurable in urinary, blood or saliva samples - Lasting effects on almost all organs, influences body metabolism, the immune system and the brain - Increase in cortisol levels -\> inhibition of the immune system, but some immune parameters are also stimulated - Deficient feedback mechanisms of the HPA-axis are associated with the development of various diseases - Allostatic load -\> reaction-oriented stress theory - Genetically determined hyper-or hyposecretion of cortisol - Biopsychosocial etiology model More recent psychophysiological stress model : allostasis and allostatic load ============================================================================= Acute stress as such is not dangerous -\> immune function is increased, danger-relevant memory contents are activated Adaptation through allostasis : the ability to achieve stability through change - Damage occurs only if stress persists and the individual is unable to regulate the stress response Une image contenant Tracé, texte, ligne, diagramme Description générée automatiquement How does (chronic) stress affect physiological stress reactivity ? ================================================================== Allostatic load : "the wear and tear that results from chronic overreactivity or underactivity of allostatic systems  Une image contenant texte, ligne, diagramme, Police Description générée automatiquement Dysfunction of HPA-axis : associated disorders and physical conditions ======================================================================  ==================================================================================================================== Stress and the immune system ============================ - Psychoneuroimmunology (newer sub-discipline of psychology) - immune system does not function autonomously, can be conditioned by external manipulation - **principle of classical conditioning** : formerly neutral stimulus is coupled with unconditioned stimulus - **conditioned change** : immune response always takes place when a formerly neutral stimulus (CS) is able to trigger or suppress an immune response after a few learning cycles, cad spatio-temporal coupling with an immunoregulatory agent (UCS) - **Ader & Cohen (1975)** : experiment with rats (immunosuppressant & sweetner) - **Buske**-**Kirschbaum & colleagues** ***: voluntary participant*** Classing conditioning ===================== - **Food** (UCS = unconditioned stimulus) **-\> saliva** (UCR = unconditioned reaction) - **Food** (UCS) repeatedly paired **with bell** (neutral stimulus) -\> **saliva** (learned : bell -\> food) - **Bell** (conditioned stimulus, CS) **-\> saliva** (conditioned reaction, CR) Une image contenant chien, mammifère, texte Description générée automatiquement Stress and the immune system ============================ Immune system is strongly **influenced by acute and chronic stress** exposure & the **individual ability to adapt to stress** **-- Immune-stimulating processes under stress** ("trafficking", where protection is needed) e.g. more immune cells in the skin during acute stress → Organism protected from infections in the short term & wound healing processes accelerated **-- Immune-suppressing processes under stress**: Reduction of lymphocytes, monocytes and natural killer cells under acute stress → Sensitivity to infections, especially with hyperreactive HPA-axis. Susceptibility to infections; increased likelihood of autoimmune diseases with a hyporesponsive HPAaxis (too little cortisol secretion) -- Medicine: Treatment of immune overreactions with cortisone (synthetic glucocorticoids), mimic the natural immunosuppressive effect of cortisol ("shutting down reaction")