Exploring the Connection Between Stress, Psychology, and Health

PSYC 1650 NOTES Chapter 13 Health psychology is a relatively new area, and developed in part as a function of the fact that most of the top 10 causes of death in the US are lifestyle diseases – – CVD, stroke, cancer, COPD, kidney disease, e.g. - we’re now living well enough and long enough to slowly fall apart – A little bit about lifestyle behaviors – they may be health-defeating or promoting behaviors Examples of the former include smoking, drinking to excess and risky sexual behaviors Many have an illusion of invulnerability optimism bias: Bad things happen to others. There are three models of health and well-being: wellness models, environmental models and the one we care about – the biopsychosocial model This was discussed because there was only a medical model of illness – a germ causes everything This model recognizes that genetics, infectious agents, environmental toxins and immune responses interact with stress, habits, appraisals, and social factors (availability of health care etc. to determine health Our conscious thoughts (and some unconscious info) does change our physiology the placebo effect – when an individual experiences the positive effects of a medication/supplement/surgery that s/he expects too (if the individual experiences unwelcome side effects they are feeling nocebo effects) Everything matters in the case of placebo effects, which are especially powerful in disorders that have more of a “cognitive” bend to them, e.g., depression or pain To put it another way, the affective component of pain seems to play a role in the placebo effect The placebo effect is INCREDIBLY powerful – one pharmaceutical executive is quoted as saying “it’s not whether or not a drug works, rather does it work better than placebo?” Believe it or not you actually see placebo effects in sham surgeries - A 2014 review of 53 trials that compared elective surgical procedures to placebos found that sham surgeries provided some benefit in 74 percent of the trials and worked as well as the real deal in about half. 1 Okay, why does stress make us get sick? A guy named Hans Selye thought about this and came up with an idea so wrong it likely cost him a Nobel prize! He talked about a general adaptation syndrome - GAS There are three stages: alarm – bells go off; resistance or adaptation – the stress response and the reattainment of homeostasis; and exhaustion if the stress continues – he’s where he goofed – he thought that here is where trouble arose – sickness occurs because the system becomes depleted of hormones – that’s incorrect autonomic nervous system (recall its two branches are the sympathetic and parasympathetic systems) – and its activation controls your response to stress The ½ that’s turned on is the sympathetic nervous system – it originates in the brain, goes through the spine, and exits to branch out to nearly every organ, blood vessel, and sweat gland in your body – it “turns on” when life gets exciting or alarming – causes increases in BP, HR, etc. Epinephrine is secreted by nerve endings in the adrenal glands (on top of your kidneys), and norepinephrine by all other sympathetic nerve endings in the body – you see those, as well as DA, active as neurotransmitters in the brain as well Now E or NE or DA are all catecholamines and can be released as a neurotransmitter in the brain, when you have release from the adrenals, it’s a hormone – often the only “title” a chemical is given depends on where it’s released from As for the brain, NE and DA “turn on” the amygdale and “off” the prefrontal cortex Now mild to moderate uncontrollable stressors cause NE and DA release in the amygdale to enhance memory consolidation – you see the development of conditioned fears here – recall arousal is important for memory formation – (remember the Yerkes Dotson Law?) This facilitation by the amygdale activation helps with HA declarative memory (for the event) and habit memories in the striatum (a subcortical area and a major input to the basal ganglia) to be expressed However, an increase of DA release in the prefrontal cortex causes cognitive dysfunction (and a lack of control makes it worse!) NE helps with the dysfunction Evolutionarily this makes perfect sense – you want to remember what it was that threatened you, and get away from it (habitual responses like running!) – and who cares about anyone/thing in your way (out with those socially accepted behaviors!) The ½ of the ANS that’s turned off is the parasympathetic nervous system – it mediates calm, vegetative activities – it promotes growth, energy storage, etc. Parts of the brain that activate one typically inhibit the other – but neither is ever completely shut off We’ve already talked about NE and EPI being important hormones in the stress response; there’s another class of hormones called the glucocorticoids that are equally important – they are a class of steroid hormones Cortisol (a glucocorticoid), remember, is the classic stress hormone – it helps prolong that initial response, and has effects on your immune system – initially it is enhancing – makes sense if you’re hurt when you’re “fighting” So initially cortisol in immunoenhancing; but longer term it becomes immune suppressive because you don’t want to become distracted by an injury If you’re stressed, also, your pancreas is stimulated to release glucagon – recall it converts stored glycogen to glucose - it raises circulating glucose levels for immediate use - again, you want energy NOW Humans tend to view stress as either threat vs challenge Threat- not having the ability to cope with it. Challenge- they are aware of the stress that will arrive, but they think they can cope with it. ● both of these are theories of how humans view stress. Studies were done on people, bringing them into a lab and placing them in stressful situations, and recording the results. Not really good how it the external validity. UNT did a study was designed to see how students view stress in the real world. When looking you can see the chemical cortisol being transmitted. Using students in the class and tested their stress over taking a test. The test is the potential stressor A couple questions asked - ‘What would you be okay with on this exam?” - “What do you think you’re gonna get?” If the subjects viewed their grades as 80 or above they assumed it was a challenge If it was a 60 or failing, it was viewed at a threat. You’re expecting the cortisol levels to rise because they are expecting stress. Splitting the results by sexes (male and female) Male’s cortisol did what was expected, they went up; Female cortisol level didn’t The moment the stress hits is the same in both sexes however the response is different. in females oxytocin is released and soothes the fight or flight in women. The results: female didn’t matter how the viewed cortisol went down. Men if they viewed as a threat cortisol levels did not change, but viewed as challenge it did rise. Around this time researcher in California came out with article talking about stress response in female’s. What’s even more shocking is 70% of psychology studies over physiology was all male’s. Due to female’s menstrual cycles, it's hard to gain control over that hormonal cycle. The idea for how women view their fight or flight response was different. The theory of Tend or befriend responseidea proposed to talk about how women view stressors. While males are more fight or flight. When human females are stressed they are much likely more likely to be in a room with OTHER females while men like to be alone. “If you ask a married couple who their best friends are the husband is gonna say the wife, his wife is going to name her best friend.” Prolactin is released from the pituitary [suppresses reproduction during stress]; both the pituitary and brain [and adrenals?] secrete the endorphins and enkephalins, which blunt pain perception So some hormones are released, and others are inhibited – the “reproductive” hormones like estrogen and testosterone; growth hormone, and insulin are all inhibited Finally, the pituitary releases ADH, aka vasopressin, which helps raise BP, and also directs the kidneys to preserve fluid (not pee) Okay – that’s the stress response, and the important components Now before we go any further, think about a “fight or flight” situation from an animal’s, versus a human’s, perspective A zebra is grazing on a field, and is suddenly being chased by a lion – new he can’t fight so he’s gonna flee – he gets away or is lunch, but either way it happens and the response is over – assuming he gets away he goes back to his regular routine! From an evolutionary perspective, it’s a perfect response Humans are different (in addition to not needing to worry about lions!) – we ruminate – worry endlessly about grades, money, relationships etc So we don’t just have one single stress response in a day, but rather a lot – and all of that cortisol builds up over a day - and remember I told you it was immunosuppressive??? Our response to a stressor differs though – remember. The response is determined to a large part by how a stressor is appraised – explain threat versus challenge (primary) and coping possibility (secondary) as defined by Lazarus and Folkman Differences between the male and female stress response lead to the realization there are sex differences “tend and befriend” vs “fight or flight” The TEND part is accomplished via the activity of oxytocin As for the BEFRIEND, a hallmark of social psychology research is the sex difference in affiliation – when stressed, F prefer to be in groups with other females, and M prefer to be alone F rats show less GC release in group housing Social support is greater in F Oxytocin causes an increase in social behavior Appraisal matters stress is unhealthy for your heart The cardiovascular stress-response is important is you want to be able to outrun that ax murderer! Top – atria – veins; bottom – ventricles-to arteries Right heart pumps blood through the lungs; left heart pumps blood to the peripheral organs The first thing that needs to happen is an increase in your HR– this happens via turning down parasympathetic tone and activating the sympathetic system [recall they oppose each other]; glucocorticoids help by activating neurons in the brain stem that stimulate sympathetic arousal, and enhancing the effects of EPI and NE on heart muscle (recall the GC’s are always there – released on a circadian rhythm) You also want to increase the force of your heart beat – the veins, which are returning blood to the heart, constrict, thus forcing the blood through them with more force and slamming into the heart – this causes the heart chambers to distend and snap back with more force of their own [this is your blood pressure – systole is the force of blood leaving the heart; diastole is the force of blood returning]] Okay, now it’s important for your survival that blood with its energy source be more available to places that need it – arteries to your muscles dilate so more blood is available, and constrict [so flow is decreased] to places like your gut You also see decreased blood flow to your kidneys – you might need to retain fluid if you’re losing blood(!) – as I mentioned earlier, your brain sends ADH to tell the kidneys to shut down and stop producing urine What about chronic stress? In the case of acute stressors [like an ax murderer] your system works exactly like you want – but what if you respond with the same response every time something bugs you? The stress-response for a psychological stressor has bad effects on a number of systems we’ll talk about – but the CV system is probably #1 on that “bad effects” list Before we even talk specifics, think of your heart as a pump and your blood vessels as hoses – use them too much too forcefully and they’ll wear out The first step in this stress-related disease is the development of hypertension – chronically elevated high BP – on its face it seems simple – stress causes your BP to rise! It’s a little more complicated – you have small blood vessels all over your body that supply nearby cells, and they need to regulate blood flow – if BP is constantly raised [recall, you’re increasing the force of blood flowing ], it’s harder for them to do their job – one thing they do is develop more muscle – strength to help them control this gushing blood – and this makes them more rigid – which increases vascular resistance , which also tends to increase BP …… Okay, so now your BP is increased – so blood is slamming into your left ventricle of your heart – this will cause it to grow in size, and you’ll develop left ventricular hypertrophy [named for the area affected]; and this will increase your chance of an irregular heartbeat Also, bigger heart area = needing more blood, maybe more than the coronary arteries can supply – [a great predictor of cardiac risk ] Also, your blood vessels undergo bifurcation, i.e., they split into smaller and smaller units to supply the cells in your body In fact, this is so well done, no cell in your body is more than 5 cells from a blood vessel – yet the circulatory system takes up only 3% of body mass – WOW! Okay, these branch points where bifurcation occurs bear the brunt of the increased pressure, and over time become damaged – torn – once this happens you see an inflammatory response – so immune cells and something called foam cells aggregate there but sym. arousal makes blood more viscous, and platelets clump together – they may get snagged on the injured vessel – by now you have an atherosclerotic plaque Okay, so stress promotes plaque formation – clinicians have forever been trying to determine how bad off someone is – they measure gunk since a lot of it builds up – another thing that sticks to these plaques is cholesterol, and that’s what is measured – LDL’s take fat to plaques, the so-called “bad cholesterol”, and its circulation increases LDL bad HDL good Now high cholesterol, especially bad cholesterol, does increase the risk of CVD, but it’s not a great predictor – 50% of MI victims have normal LDL levels Recently, the vessel damage has been shown to be a better predictor of CVD than circulating crud – so how to measure damage? C-reactive protein [CRP] is non specific it is released for any and all inflammation. made and secreted by the liver in response to injury and goes to the site to amplify inflammation – it’s a much better predictor of CVD than cholesterol - the new measurement that seems to be important So you’ve got these plaques – blood is still rushing through your vessels – maybe it tears a plaque loose – now you have a thrombus – a clot – if it clogs up a coronary artery you’ll have a heart attack, a vessel in the brain and you’ll have a stroke Visceral fat - the fat around your stomach Gluteal fat- the fat in your ass Cortisol helps with depositing fat to save for energy, but it prefers to store it in the stomach. The bad thing is, is that the fat cells tend to move to other places in the body like the liver. Exercise doesn’t help you lose weight, but is EXTREMELY important. Reduces stress. Odds are it’ll make you more hungry. Psychoneuroimmunology (PNI) Before I tell you about PNI, I need to give you a brief introduction to the immune system The immune system has two major characteristics: the ability to differentiate self from non-self and to exhibit specificity and memory Self vs non-self Self is you, e.g., your own cells and organs, and your immune system is happy with you! Well, for the majority of folks– in cases where this distinction breaks down you see autoimmune disease, i.e., the person’s own immune system attacks them; non-self is not you – it can be a virus, bacteria, or MY kidney – those things are foreign to your immune system and it will work to get rid of them all (that’s why folks who receive an organ transplant (kidney, heart, etc) are on immune suppressive drugs FOR LIFE – their immune system is always trying to get rid of it! The immune system will attack any foreign object, like a transplant to help lessen the immune response. So your body doesn’t fight back and attack the new organ Antigen- things that aren’t non-self that will cause an immune response. Specificity and memory If you are bitten by a rabid dog, your immune system will produce immune fighters called antibodies to help combat the rabies – now those antibodies are specific to rabies – if later you’re exposed to tetanus because you fell over a wire fence (you’re having a really bad time!) the rabies antibodies won’t do anything against tetanus – they’re specific to rabies. That’s why when you get a shot the dead virus is injected in you so your body can make antibodies specific to target that disease. The first time you come into contact with something like a virus (all things that cause an immune response are called antigens), your immune system will produce antibodies against that virus – the initial (called primary) immune response takes (about 8-10 days) BUT if you are re-exposed to that same virus again, a secondary immune response will occur much faster (about 3-4 days), and will be stronger – your system remembers the antigen! After the primary response, your system includes generation of some “memory cells” that are ready to respond quickly if you ever see the antigen again That’s what vaccines are based on – for example, you receive a flu vaccine with typically 4 flu viruses (a part or a whole dead virus so they cannot make you sick) in it, your immune system responds to them, so if in the “real” world you are exposed to them your system will respond so rapidly you can beat the virus and not get the flu There are many important cells in the immune system but I’ll just mention a few: T cells – 2 types helper and cytotoxic helper T’s help with all kinds of immune responses including those caused by an antigen like a flu virus or if your own cells develop cancer (they help cytotoxic T cells in that case) Cytotoxic specifically help with your own cells becoming altered due to cancer for example B cells – these cells produce antibodies Macrophages – do about everything – they on their own destroy some antigens and help T cells and B cells combat them as well. Are basically instigators, present things to other immune cells to get the process started. Neutrophil, fight against virus but are killed in the process. They will kill something and kill themselves. That’s what puss is, like in pimples white heads. Okay hold that thought for now - so how does PNI come into existence? Classical Conditioning of Immune Responses I want to talk about the study that got the whole thing started – cool thing was it was due to an experiment performed by a behavioral psychologist! Dr. Ader – he was working with rats doing taste aversion studies, and wanted to see if he could extinguish a taste aversion (taste aversion is a form of classical conditioning – I’m not sure I ever said that specifically but it is), so he did the following study: water deprived all animals – used sugar water as a CS, and the drug Cytoxan as his US now all he knew about Cytoxan was that it produced nausea in rats – made them sick after conditioning he got a great taste aversion - the control animals drank up the sugar water when re-exposed to it, and the conditioned rats wouldn’t touch it then he started extinction trials – recall in classical conditioning you simply reexpose all animals to the CS and try to extinguish the response. So he repeatedly re-exposed all rats to the sugar water on successive days. But his rats started to die! Not all of them though – only ones in the conditioned group – the ones with the taste aversion He wasn’t giving them the drug anymore so was sure it wasn’t some drug effect, so he went to the literature to find out more about it (should have done that before he started!). Cytoxan is a drug typically used to fight cancer – it kills rapidly dividing cells – that’s what cancer cells are. Unfortunately that’s what immune cells are too. So he started to think maybe every time I’m re-exposing them to the sugar water I’m not only recalling the stomach ache in the rats, but their immune system is getting suppressed a little each time too So he asked an immunologist friend if that was possible, and Dr. Cohen said “I think you’re nuts but let’s test it”. He thought it was nuts because at that time it was thought that the immune system functioned completely on its own – it had nothing the do with the brain or any other body part at all! (oh how far science has come!) So they did the study, but right before they re-exposed the rats to the sugar water on test day all rats in both groups got an antigen that would cause antibody production Now they also added a control group that was conditioned - got the sugar water (CS) followed by the Cytoxan (US) on conditioning day but simply weren’t tested to control for any residual drug effects – a CS0 group After testing they waited a few days and then checked the rats’ antibody levels – the Control group had a great antibody response, the CS0 group a little low (residual drug effect) and the CS group significantly lower- bottom line YOU CAN CONDITION IMMUNE RESPONSES Now at the time this was HUGE news! If you’re talking about learning (classical conditioning) you’re talking about the brain; but no one thought the brain had anything to do with the immune system Research took off after that, and it was determined there were multiple ways the systems (and others) all communicated HIV positive patient called Ader about the drug study he did with a little girl with lupus, conditioning her with the medications. He tried to do same the thing but the physician has to sign off on the okay for it. Physicians don’t care about the side effects as long as it beats the main effect. For example: 1. There is neural innervation of immune tissue 2. On immune cells there are receptors for E, NE, DA etc. AND cortisol 3. Immune cells produce all of these chemicals as well Now remember, all of these things (E, NE etc and cortisol) are released as a part of the stress response, and all can affect your immune system Cortisol, in addition to being immunosuppressive, is also neurotoxic – in excess over a long period of time it kills neurons! okay, so you see all of these changes – we know of the connections between the brain and immune system, but can what you think REALLY affect how you feel? To put it another way, the primary question was “do they mean anything”, i.e., are they clinically relevant? Sheldon Cohen (a different Cohen from the one who worked with Ader!) and colleagues at Pittsburgh have been studying this question for about 30 years – they published a seminal article in The New England Journal of Medicine years ago indicating that IT DOES it was well controlled study, performed it England (had to laws in the US regarding studies you can’t just give people viruses without a cause), exposed subjects to one of 5 possible cold viruses, and showed stress was correlated with cold symptoms – the N was huge – around 400 SUBJECTS (Ss) subjects were exposed to one of 5 cold viruses or saline 2 days before and 7 after Ss were quarantined in apts., either alone or in groups of two or three), and subjects were monitored daily by a clinician for a checklist of symptoms Researchers took consideration of the participants health practices (smoking, drinking, sleep) were assessed, as was personality – introversion-extroversion, self-esteem, and control psychological stress was assessed using 3 questionnaires – the results were combined to form a single stress score where a high no. = high stress The cold virus was administered nose spray with either the cold virus or saline, and the participants were kept in the apts for week while they were studied. Researchers collected tissues or mucus to check on everything. 82% of subj. who received the virus were infected (19% of saline were too! That’s what living in groups will do) psychological stress was associated with an increased risk of acute infectious respiratory illness in a dose-response manner (the stress score) - the stress index was associated with host resistance and not with differential exposure (i.e., lived alone vs group housed) to the virus, the type of virus, and differences weren't due to behavioral health practices, differential immune cell counts, or antibody levels Also wasn’t due to personality variables - personal control, self-esteem, or introversion-extroversion, the only thing that mattered was if they were high stressed they got the virus. Looked at support systems and interpersonal stress levels. Checked the participant’s antibody results to see if there was a relationship between the 30% that were clinically sterile after the first round of injections, had the lowest level of stress, and had the highest amount of social support. Worked on other things as well, - Patients received a punch biopsy on the roof of their mouth. (something that punctures a hole) found the same results, low stress is always a good thing. In vaccination, status, anything. Other important studies in PNI Autoimmunity – if you think about it, stress suppresses the immune system Autoimmunity is the result of an overactive immune system, so stress should be wonderful for these folks, but it’s not – why? Because the hormone cortisol works differently centrally as opposed to peripherally – it is immune enhancing in the brain and immune suppressing peripherally Many studies indicate that reducing stress improves the autoimmune disease MS, e.g. Cancer and the PNI - Study done forever ago, researchers stumbled upon gold. Study done with rats. Rats and control – control of a stressor led to a significant decrease in susceptibility to cancer; generally even a perception of control matters. Rats set up in boxes with a shock system, each box had a lever to stop the shock. It would go down the line like a domino. One lever controlled the shock the other was just a placebo lever that didn’t do anything. They each received the same level of shock. After doing this trial for a couple of weeks they injected every single rat with a cancer cell line that was certain to cause cancer in 50% of the time. And watched what happen. If a month went by with no tumor growth or presence, it was deemed the rats were cancer free. Group of rats that got shocked but had the placebo lever - The % of animals in that group that DID NOT develop cancer was 23%. Rats with notihing - 50% of rats with no treatment reported no cancer. Group that could control their shock. - 63% of the rats in the group DID NOT develop cancer. Cancer For the longest time, there was no idea how or why stress would have an effect on cancer. In the last decade tho, there has been a lot more knowledge has been dedicated to the subject. And much of the stress hormones were released with the cancer…. - Normal tissue: well-regulated equal to the number of cells dying and alive. 10 die a day 10 are born You can have too many cells growing or too many cells dying, either way, is not good. Cancer starts somewhere in your body. Some cancer cells will travel through the bloodstream and start growing somewhere else. This action by itself is strange. Normal cells don’t do this, but cancer cells do. Believed for the longest that your immune system could keep cancer in check, sadly cancers can invade the immune system. Tumor escape systems. There are multiple ways cancer cells can go undetected by your immune system. Use to think that it was caused by something external for us to have cancer internally. But that is not true. Turns out our body had these onchges. Normally they are good and help with the growth and development of cells, BUT if these mutate they will turn into cancer. Luckily the body has tumor suppressant genes that will fight the growth of tumors. The tumor is just swelling inside the body, it could be caused by cancer, but doesn’t always have to be. Stress can lead to cancer or set up an environment in which cancer can thrive. correlation n between animal studies and humans shows this. Why? - The environment of being under constant stress can lead to chronic inflammation. Faster BP and reduced bloodlfow. One thing that seems to help with cancer is social support. POSITIVE social support. (support groups, family, friends, therapy) behavioral support. Someone who will help you do chores to help ease stress and does help beat cancer.