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Hormonal and neural aspects of stress and anxiety. The science of stress physiology. Hans Selye. Defining “stress”. Etymology: Latin strictia, strictus meaning "compressed” The broadest definitions of stress include the entire complex sequence of events:
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The science of stress physiology • Hans Selye
Defining “stress” • Etymology: Latin strictia,strictusmeaning "compressed” The broadest definitions of stress include the entire complex sequence of events: • the event that requires some change (external or mental; real or imaginary), • internal mental processes (perception, interpretation of the event, learning, adaptation, or copingmechanisms) • emotional reactions • behavioral-bodily reactions (nervousness, sweating, stumbling over words, high blood pressure). • In a more limited usage, stress is the upsetting situation. However, most of us use the term stress loosely for both the threatening situation and the anxious reaction.
Stress • Stress may refer to meeting any "demand" made on us, even good, reasonable, enjoyable ones, which throw the body out of balance.
Bad stress • Any change outside our control • Daily hassles (constant nagging, flat tire, an uninvited visitor, a headache, a long form to be filled out)
Frustration, threat, conflict • Stressors may be real or imaginary, past or future obstacles • If something (or someone) has interfered with our "smooth sailing" in the past, it is called afrustration or a regret. It may upset us and depress us. • If the obstacle is expected in the future, it is called a threat. This may be an accurate or an unrealistic expectation; in either case it causes anxiety and worry. • A common human dilemma is when our own inner wishes, needs, or urges push us in different directions. This is the world of psychological conflict.
Internal conflict • Ambivalence – you want something but shouldn’t have it because it’s bad for you
Internal conflict • Better avoid it because if I start I won’t be able to stop
Internal conflict • You want them both, you can only have one
Internal conflict • Too many complex choices
Internal conflict • Choosing between two unappealing options
Other external and internal stressors (Schaffer, 1982) External • noise, polluted air, overcrowding, poor lighting (those dreadful fluorescent lights!) • unpleasant relationships • uninteresting work (mindless repetitive tasks) or poor conditionsof work • too much or too little responsibility • toomany "rules." (mind the gap!) Internal • poor diet, little exercise • physical strain on the body, rushing or being unable to adjust to the pace of others • having no time for yourself • sexual frustration
Studying stress response in primates Doctor Robert Sapolsky, professor of neuroscience and human behaviour biology at Stamford University
Why study stress in primates • perfect models for westernized stress-related diseases because “like us they have the luxury of generating psycho-social stress”. • This particular group of baboons studied by Sapolsky live in ideal conditions in the Serengeti ecosystem. • They are not stressed by predators or the threat of malnutrition, but by each-other • “If you’re unhappy it’s because some other baboon has worked very hard to bring that state about. ‘’
What is stress about in a baboon’s world? Dominance hierarchies • Baboons have the highest aggression rates of nonhuman primates. • The leading cause of death in male baboons is male baboons. • Rank is a powerfully organizing feature of their society, with an overall stabilizing effect. If you’re smart enough to know your place there will be fewer fights. • To establish your high rank you have to win the right fights. • Common threats of violence
Rank • Life is very different for a high-ranking versus a low-ranking baboon • Rank influences who grooms who, what food and females you get access to.
The making of high-ranking baboons • Big, muscular, with long canines • Also social intelligence, impulse control (knowing which provocations to ignore) • Bodies that deal well with stress. The higher rank – the lower the level of glucocorticoids in the bloodstream. • Knowing when to turn the stress response on.
Profile of a low ranking baboon • A sluggish response to stress and sluggish recovery from stress • Elevated glucocorticoid secretion in the absence of stress because as a low ranking baboon you’re always stressed • Lack of outlet for frustration, lack of sense of predictability and control • Subordinate baboons have the same profiles as depressed humans (elevated basal levels of cortisol, CRF hyper secretion, blunted pituitary sensitivity to CRF) • Low ranking baboons have elevated stress related disease and reduced immunity
Differences in temperament and personality styles • Can they tell the difference between threatening and neutral interaction? • Do they take control? • Can they tell whether you won or lost a fight? • Do they have coping outlets? • Social affiliation: How often they groom; how often do they stay in contact with someone else; how often do they play with an infant?
Baboon societies and cultures Social rank is important but much more important is the kind of society they live in. • Stable societies: being high ranking is best • Unstable societies (chaotic, lots of conflict): being high rank is stressful • Your personal experience in that society. • The chance emergence of a new culture.
The human underdog Correlation between social rank and health • Whitehall I and II studies , examined over 28,000 civil servants, beginning in 1967. • Men in the lowest grade of employment (messengers, doorkeepers, etc.) had a mortality rate three times higher than that of men in the highest grade (administrators). • High blood pressure at work was associated with greater "job stress," including "lack of skill utilization," "tension," and "lack of clarity" in tasks assigned. • The higher blood pressure among the lowest grade servants was found to be related to the highest job stress score. • Lack of control, predictability and outlets enhances the risk of stress-related disease
Fear, phobia, panic, anxiety • All these affects are on a continuum • Fear is a here-and-now bodily felt, involuntary reaction when you are faced with a dangerous, life threatening situation. • Phobia is excessive fear, an over-reaction to a situation or object that objectively or statistically doesn’t represent a risk: phobias of heights, flying, bugs, enclosed places, open spaces, or of speaking in public) • Panic attacks are sudden, overwhelming reactions, often without an obvious external cause, usually involving rapid breathing, heart palpitations, fear of dying, and a frantic attempt to get to safety.
Anxiety Anxiety is a pervasive sense of disquiet, unease, which arises mainly in interpersonal contexts. The presence of anxiety is deeply interlinked with our history and beliefs about self, others and the world. Anxiety is about anticipating something unpleasant: punishment, being shamed, humiliated, judged, found out, disappointing, seen as unworthy of respect and seen as failing by others. It is a fear of not meeting expectations and not being able to master our surrounding environment and relationships.
Signs of anxiety Bodily involuntary responses • muscles tight or aching, nervous tics, hands unsteady, restlessness, touching yourself repeatedly, clearing your throat • Frequentcolds, pain, upset stomach, sweating, skin problem or itch, stiff posture, holding things tightly, strong startle response, headaches, high blood pressure, ulcers, heart disease, colitis • hemorrhoids, rashes, diarrhea, or frequent urination. Behavioral-emotional signs • hyperactivity, walking or talking faster, in a hurry, irritation with delays, panicky, blushing, getting tongue-tangled, avoiding people • nervous habits (strumming fingers, eating, smoking, drinking), changing habits (becoming less or more organized), poor memory, confusion, stumbling over words, inattentiveness, excessive worrying • preoccupation with a certain situation, obsessive thoughts, compulsive actions, outbursts of emotions, bad dreams, apathy, etc.
Brain structures involved in coordinating fear and stress responseThe orbito-limbic system: Amygdala, Hypothalamus, Hippocampus, the Prefrontal cortex
General Anxiety Disorder (GAD) • A chronic, debilitating condition consisting of excessive worry, disruptive anxiety, and distressful tension that has lasted for at least 6 months and maybe for years. • It is the second most common psychiatric disorder (after depression); about 5% of the world's population suffers with this disorder. • GAD frequently results in sleeplessness, irritability, poor concentration, and fearful hyper-vigilance.
