Health Psychology Lecture Notes PDF

Heliopolis Modern Language Schools The American Division The Science, Technology, Engineering & Mathematics [STEM] Program Health Psychology Biopsychosocial pathways to health and illness Instructor: Mrs. Rana Hesham  The term “psychology”: It is the scientific stud...

Heliopolis Modern Language Schools The American Division The Science, Technology, Engineering & Mathematics [STEM] Program Health Psychology Biopsychosocial pathways to health and illness Instructor: Mrs. Rana Hesham  The term “psychology”: It is the scientific study of the mind and behavior Psychologists are involved in studying and understanding mental processes, brain functions and behavior. What is the biopsychosocial perspective on health and illness? The biopsychosocial model postulates that health and illness are influenced by: Psychological factors (e.g. cognition, emotion, personality) Social factors (e.g. people in your social world, social class, ethnicity) Biological factors (e.g. viruses, lesions, bacteria) Basic features of the nervous system: Central nervous system and peripheral nervous system The nervous system has two distinct parts: 1. The central nervous system. 2. The peripheral nervous system. Basic features of the nervous system The nervous system consists of the brain, the spinal cord and the nerves (bundles of fibres that transmit information in and out of the nervous system). Functions of nervous system 1. It allows us to adapt to changes within our body and environment by using our five senses (touch, sight, smell, taste, sound) to understand, interpret and respond to internal and external changes quickly and appropriately. 2. The brain is the central part of the nervous system and it helps control our behavior as it receives and sends messages for the rest of the body through the spinal cord Basic features of the nervous system The brain has three major anatomic components: the forebrain, the midbrain and the hindbrain A- The forebrain consists of: 1. The telencephalon, which is composed of the cerebrum and limbic system. 2. The diencephalon, which comprises the thalamus and hypothalamus. Basic features of the nervous system: The anatomy of the brain The cerebrum is the largest part of the human brain and is divided into the two halves – the left and right cerebral hemispheres – that are connected in the middle by a bundle of nerve fibres called the corpus callosum. The upper part of the cerebrum is the cerebral cortex (its outermost area). This is subdivided into 4 lobes. It is involved in speech, thought and emotion perceives and interprets sensations like touch, temperature and pain It is involved in hearing and aspects of memory storage It detects and interprets visual images Basic features of the nervous system: The anatomy of the brain The limbic system consists of the amygdala and hippocampus among other structures. This system interacts with the endocrine system and the autonomic nervous system. It plays an important role in motivational and emotional aspects of behaviors such as eating, drinking and aggression. It is also involved in aspects of memory processes Basic features of the nervous system: The anatomy of the brain The second major division of the forebrain is the diencephalon. Its two most important structures are the thalamus and the hypothalamus The thalamus is thought to have multiple functions and plays an important role in regulating states of sleep, arousal and consciousness Basic features of the nervous system: The anatomy of the brain The hypothalamus is located below the thalamus and although it is a relatively small structure it is very important as it regulates the autonomic nervous system and the endocrine system. It controls how individuals respond to stressful encounters. It oversees the basic behaviors associated with the survival of the species: fighting, feeding, fleeing and mating, often referred to as the four Fs! Basic features of the nervous system: The anatomy of the brain The midbrain consists of two major parts: the tectum and the tegmentum. The midbrain, including the brain stem, regulates critical bodily functions such as breathing, swallowing, posture, movement and the rate at which the body metabolizes foods. Basic features of the nervous system: The anatomy of the brain The hindbrain has two major divisions: the metencephalon and the myelencephalon. Metencephalon comprises the cerebellum and the pons myelencephalon contains one major structure, the medulla oblongata (usually referred to simply as the medulla). The cerebellum is involved in coordinating the body’s movements and the pons has been implicated in sleep and arousal. The medulla controls vital functions linked to the regulation of the cardiovascular system and respiration Basic features of the nervous system: The spinal cord and nerve cells The spinal cord is a long, delicate structure that begins at the end of the brain stem and continues down to the bottom of the spine. It carries incoming and outgoing messages between the brain and the rest of the body. The brain communicates with much of the body through nerves that run up and down the spinal cord. the spinal cord plays an important role in responding to pain stimuli. The nervous system contains 100 billion or more nerve cells that run throughout the body. Basic features of the nervous system: The spinal cord and nerve cells A nerve cell, called a neuron, is made up of a large cell body and a single, elongated extension (axon) for sending messages. Neurons usually have many branches (dendrites) for receiving messages. Nerves transmit messages electrically from the axon of one neuron to the dendrite of another (at the synapse) by secreting tiny amounts of chemicals called neurotransmitters. These substances trigger the receptors on the next neuron’s dendrite to start up a new electrical impulse. Basic features of the nervous system: Central nervous system The peripheral nervous system (PNS) is a network of nerves that connects the brain and spinal cord to the rest of the body. The PNS is further subdivided, according to its function, into the: 1. somatic nervous system (SNS). 2. autonomic nervous system (ANS) Basic features of the nervous system: Central nervous system The SNS is concerned with coordinating the ‘voluntary’ body movements controlled by the skeletal muscles. The ANS regulates internal body processes that require no conscious awareness, for example, the rate of heart contractions and breathing, and the speed at which food passes through the digestive tract. Basic features of the nervous system: Central nervous system The ANS is subdivided into the: 1. sympathetic division. 2. parasympathetic division. Endocrine System The endocrine system is an integrated system of small glands that work closely with the ANS and are extremely important for everything we do! Similar to the nervous system, the endocrine system communicates with many different parts of the body, however, it uses a different ‘signaling system’. Whereas the nervous system uses nerves to send electrical and chemical messages, the endocrine system only uses blood vessels to send chemical messages Endocrine System Each of the endocrine glands, once activated, secretes chemical substances called hormones into the bloodstream which carry messages to different parts of the body. There are a number of endocrine glands located throughout the human body such as the adrenal glands, gonads, pancreas, thyroid, thymus and pituitary gland Endocrine System: The pituitary gland The pituitary gland is located just below the hypothalamus and is considered the ‘master’ gland because it regulates the endocrine gland secretions. It has two parts: the anterior pituitary and the posterior pituitary. Endocrine System: The pituitary gland Anterior pituitary secretes growth hormone (GH), adrenocorticotrophic hormone (ACTH), thyroid stimulating hormone (TSH), follicle stimulating hormone (FSH) and luteinizing hormone (LH) Endocrine System: The pituitary gland Posterior pituitary releases oxytocin and vasopressin (ADH) Endocrine System: Functions of pituitary gland 1-The pituitary gland plays an important role in the regulation of the growth of body tissues (through release of GH). 2-The development of the gonads, ovum and sperm (through the release of FSH and LH) 3-Stimulating lactation (through the release of oxytocin) 4-Maintaining blood pressure (through the release of vasopressin). -However, it also releases ACTH (after stimulation by the hypothalamus) which stimulates the adrenal cortex – this is known as the hypothalamic–pituitary–adrenal (HPA) axis response. Endocrine System: The adrenal gland There are two adrenal glands located on the top of each kidney. It is divided into two parts: the adrenal medulla, which secretes the hormones adrenaline and noradrenaline (also known as epinephrine and norepinephrine), which act on the internal organs in the same way as neurons in the nervous system. They increase heart rate and mobilize glucose into the blood among other things Endocrine System: The adrenal gland The outer portion of the adrenal gland, called the adrenal cortex, produces mineralocorticoids and glucocorticoids. Mineralocorticoids hormones act on the kidneys to conserve salt and water by returning them to the blood during urine formation. Glucocorticoids hormones are secreted when we encounter stressors in order to help the body respond appropriately. One of the most important glucocorticoids is cortisol and as such it is frequently referred to as the ‘stress hormone’. The Stress Response What happens when you experience stress? Two systems are activated. The first and easiest to activate is the sympathetic adrenal medullary (SAM) system and the hypothalamic–pituitary–adrenal (HPA) axis. Scientists say that activating the SAM system ‘can be likened to lighting a match whereas activating the HPA axis is like lighting a fire. The HPA axis is only activated in extreme circumstances The Stress Response: The sympathetic adrenal medullary (SAM) response system When an individual is suddenly under threat or frightened, their brain instantly sends a message to the adrenal glands which quickly release noradrenaline that in turn activates the internal organs. This is the basic ANS sympathetic division response to threat. However, at the same time, the adrenal medulla releases adrenaline which is rapidly transported through the bloodstream in order to further prepare the body for its response. This system is known as the sympathetic adrenal medullary (SAM) system The Stress Response: The sympathetic adrenal medullary (SAM) response system Solid line : SAM When an individual is suddenly under threat or frightened, their brain instantly sends a message to the adrenal glands which quickly release noradrenaline that in turn activates the internal organs. This is the basic ANS sympathetic division response to threat. However, at the same time, the adrenal medulla releases adrenaline which is rapidly transported through the bloodstream in order to further prepare the body for its response. This system is known as the sympathetic adrenal medullary (SAM) system The Stress Response: The sympathetic adrenal medullary (SAM) response system Within moments adrenaline and noradrenaline have the entire body on alert, a response sometimes called the fight or flight response. as a result breathing quickens, the heart beats more rapidly and powerfully, the eyes dilate to allow more light in, and the activity of the digestive system decreases to permit more blood to go to the muscles. This effect is both rapid and intense. The Stress Response: The hypothalamic–pituitary–adrenal (HPA) axis response system When an individual experiences an unpleasant event in their environment that they perceive as stressful, the hypothalamus (the H in HPA) releases a chemical messenger called corticotrophin releasing factor (CRF). Once released, CRF is transported in the blood supply to the pituitary gland (the P) where it stimulates the release of adrenocorticotrophic hormone (ACTH). The Stress Response: The hypothalamic–pituitary–adrenal (HPA) axis response system dashed line : HPA When an individual experiences an unpleasant CRFevent in their environment that they perceive as stressful, the hypothalamus (the H in HPA) releases a chemical messenger called corticotrophin releasing factor (CRF). Once released, CRF is transported in the blood supply to the pituitary gland (the P) where it stimulates the release of adrenocorticotrophic hormone (ACTH). The Stress Response: The hypothalamic–pituitary–adrenal (HPA) axis response system ▪ ACTH travels through the circulatory system to the adrenal (the A) cortex where it stimulates production of the glucocorticoid cortisol – known as the ‘stress hormone’ ▪ Cortisol increase access to energy stores, increase protein and fat mobilization, and decrease inflammation. ▪ Therefore, when an individual experiences stress, the release of cortisol triggers excess energy stored in the muscle and liver as glycogen to be liberated and broken down into glucose ready for utilization by the muscles and brain. The Stress Response: The stress response and cardiovascular disease When we are exposed to frequent daily pressure as well as long-lasting, chronic stressors. As a result, the stress response system is repeatedly activated and the cardiovascular system is potentially exposed to excessive wear and tear. Overtime, such repetitive activation may contribute to future ill health by increasing cardiovascular disease risk The Stress Response: The stress response and cardiovascular disease This may result in the development of atherosclerosis, that is, the build-up of fatty plaques in the inner lining of the blood vessels which leads to the narrowing of the arteries. The increase in blood pressure as a result of the repeated activation of the SAM system may cause damage to the lining of the blood vessels, thus allowing access to fatty acids and glucose At the same time, activation of the HPA axis leads to the release of cortisol which increases the liberation of glucose from glycogen stores. These processes taken together increase the likelihood that chronic stress may lead to a build- up of plaque. The development of plaque can have serious health consequences The Stress Response: The stress response and cardiovascular disease The first symptom of a narrowing artery may be pain or cramps at times when the blood flow cannot keep up with the body’s demands for oxygen. During exercise, an individual may feel chest pain (angina) because of the lack of oxygen reaching the heart Also, this person may experience leg cramps because of lack of oxygen to the legs. The Stress Response: The stress response and cardiovascular disease However, more seriously, if the coronary arteries supplying the heart become ‘blocked’, which may happen if increased blood pressure in a narrowed artery sheers off a section of plaque, this can lead to a myocardial infarction (or heart attack) where part of the heart muscle (deprived of oxygen) dies. If blood flow to the brain is obstructed, this can result in a stroke where part of the brain dies. The Stress Response: The stress response and cardiovascular disease Research has found that acute (i.e. short-lived) and chronic (long-lasting) stress are both associated with the development of cardiovascular disease. Scientists examined the impact of different work stressors and marital breakdown on coronary heart disease mortality during a nine-year follow-up period. These researchers found that an increasing number of different work stressors and being divorced were associated with an increased risk of cardiovascular-related deaths during the study. The Stress Response: The stress response and cardiovascular disease Another study investigating the impact of an acute stressor found that admissions to hospitals in England increased on the day following England losing to Argentina in a penalty shoot-out in the 1998 Football World Cup. The authors argue that their results suggest myocardial infarction can be triggered by emotional upset, such as watching your football team lose an important match! Biopsychosocial aspects of pain we can all think of episodes when someone’s perception of pain has been influenced by cognitive, emotional or social factors. For example, we are less likely to experience pain when we are distracted by the demands of taking part in a competitive sporting event. Biopsychosocial aspects of pain: The role of meaning in pain A physician called Beecher treated many soldiers who had been badly wounded and found that 49% reported being in ‘moderate’ or ‘severe’ pain with only 32% requesting medication when it was offered. However, several years later when he was treating civilians with similar if not less severe wounds after having undergone surgery, he found that 75% of the civilians reported being in ‘moderate’ or ‘severe’ pain with 83% requesting medication Biopsychosocial aspects of pain: The role of meaning in pain Beecher accounted for these stark differences in terms of the meaning the injuries had for the soldiers compared to the civilian surgical patients. For the soldiers their injuries represented the end of their war and they could look forward to resuming their lives away from the dangerous battleground. In contrast, for the civilians, the surgery represented the beginning of a long and challenging disruption to their lives. Biopsychosocial aspects of pain: The role of meaning in pain Theories of pain specificity theory Pattern theory It assumes that we have a separate It assumes that a separate sensory sensory system for perceiving pain system does not exist but instead similar to hearing and vision. receptors for pain are shared with the other senses. Biopsychosocial aspects of pain: The role of meaning in pain Theories of pain specificity theory Pattern theory It posits that the ‘pain system’ has its own set of When given that mild and strong pain special pain receptors for detecting pain stimuli and stimulation uses the same sense modality, its own peripheral nerves which communicates via a this theory suggests that only intense separate pathway to a designated area in the brain for stimulation will produce a pattern of the processing of pain signals. neural activity that will result in pain. Biopsychosocial aspects of pain: The role of meaning in pain However, none of these early theories can explain the role of psychological factors in pain perception. For example, they cannot account for how cognitive, emotional and social factors such as the meaning of pain can influence the experience of pain. Biopsychosocial aspects of pain: Gate-control theory of pain Gate-control theory proposes that a neural gate in the spinal cord can modulate incoming pain signals and that a number of factors influence the opening and closing of the gate, which are: 1. The amount of activity in pain fibres. 2. The amount of activity in other peripheral fibres. “ relieving fibres” 3. Messages that descend from the brain (or central nervous system). When the neural gate receives information from each of these sources it decides whether to open or close the gate. When the gate is open, pain is experienced Biopsychosocial aspects of pain: Gate-control theory of pain The theory postulates that the gating mechanism is located in the substantia gelatinosa of the dorsal horns in the spinal cord. 1. When we are exposed to a painful stimulus the gating mechanism receives signals from pain fibres (A-delta and C- fibres) located at the site of the injury, other peripheral fibres (A-beta fibres) which transmit information about harmless stimuli, and the brain (or central nervous system) to open the gate. Biopsychosocial aspects of pain: Gate-control theory of pain 2. The pain fibres then release a neurotransmitter called substance P that passes through the gating mechanism (substantia gelatinosa) and stimulates transmission cells that in turn transmit impulses to specific locations in the brain (e.g. thalamus, limbic system, hypothalamus). When the activity of the transmission cells reaches a critical threshold level we experience pain with greater pain intensity associated with greater activity. 3. Once the pain centres in the brain have been activated, we are able to respond quickly to remove ourselves from danger Biopsychosocial aspects of pain: Gate-control theory of pain ✓ Note: The brain produces its own pain relieving chemicals in the form of endorphins that inhibits the pain fibres from releasing substance P which subsequently reduces the experience of pain. Biopsychosocial aspects of pain: Gate-control theory of pain Various brain processes such as anxiety, distraction, and excitement have the capacity to influence this neural activity by releasing chemicals such as endorphins and therefore the opening and closing of the gate Biopsychosocial aspects of pain: Gate-control theory of pain From a biopsychosocial point of view, this is the most important component of gate control theory as it provides a clear route through which cognitive, emotional and social factors can influence pain perception Biopsychosocial aspects of pain: Gate-control theory of pain Conditions that open the gate Physical conditions: Extent of the injury Inappropriate activity level Emotional conditions: Anxiety or worry Tension Depression Mental conditions: Focusing on the pain Boredom Biopsychosocial aspects of pain: Gate-control theory of pain Conditions that close the gate Physical conditions: Medication Counter stimulation (e.g. heat or massage) Emotional conditions: Positive emotions (e.g. happiness or optimism) Relaxation Rest mental conditions Intense concentration or distraction Involvement and interest in life activities Biopsychosocial aspects of pain: Neuromatrix theory of pain The central tenets of the theory are: The areas of the brain linked to particular parts of the body continue to be active and receive inputs even if a body part no longer exists. We can still experience the qualities of the human condition, including pain, without receiving input from the body. Biopsychosocial aspects of pain: Neuromatrix theory of pain The neuromatrix theory suggests that pain is produced by patterns of nerve impulses. These impulses come from a neural network in the brain known as the “body-self neuromatrix.” Everybody has their own distinct neuromatrix created through genetics and modified over time through sensory experience and memory. This neural network consists of cyclical, feedback loops between three of the brain’s main neural circuits: the thalamus, limbic system and the cortex. The neuromatrix can process ‘experiences’ such as pain without receiving direct input from the body Biopsychosocial aspects of pain: Neuromatrix theory of pain When the neuromatrix receives sensory inputs, they are processed and become imprinted on the matrix creating what is known as a neurosignature. The neurosignature is projected to areas of the brain where the flow of nerve impulses is transformed into a constantly changing stream of awareness. An action neuromatrix is then activated to signal appropriate movements when pain is experienced (e.g. remove hand from hot iron). Biopsychosocial aspects of pain: Neuromatrix theory of pain Patterns of nerve impulses can be triggered by a painful stimulus, such as an injury or illness; however, they can also be triggered by other factors, such as chronic stress. The theory offers an explanation for pain conditions, such as phantom limb pain. For example, with phantom limb pain, when the neuromatrix does not receive input from a missing limb, abnormal “neurosignature” (patterns of activity) in the brain occur. These abnormal neurosignature result in phantom limb pain. Psychoneuroimmunology The term psychoneuroimmunology or PNI describe this new area of science that explored the interaction between psychological processes and the nervous and immune systems. Two areas that have received particular attention are: 1-Respiratory infectious illness 2-Wound healing Psychoneuroimmunology: The immune system The human body has the capacity to mount two types of immune defence: 1. Cell-mediated immunity. 2. Antibody-mediated immunity. Psychoneuroimmunology: The immune system T and B cells operate very differently when attacking infectious agents. The T cells bring about cell-mediated immunity while the B cells bring about antibody- mediated immunity Psychoneuroimmunology: The immune system Cell mediated response: when an infectious agent enters the body, it is recognized by a type of monocyte called a macrophage, which presents the infectious agent to a T helper cell and releases interleukin-1 (IL-1; a type of protein released from cells to influence the activity of other cells), this in turn stimulates T-helper cell activity. As a result, the T helper cells then release interleukin-2 (another protein) which triggers the spread of T cells and eventually the release of cytotoxic killer cells which attack and destroy the infectious agent Psychoneuroimmunology: The immune system Antibody-mediated immunity The initial stages are similar, such that there is collaboration between macrophages and T helper cells. However, in this case, the T helper cells stimulate the spread of B cells leading to the secretion of antibodies which identify and bind to specific features of the infectious agent. The antibodies then immobilize and destroy the pathogen Stress and the immune system Can stress alter immune functioning? There is evidence to show that stress can suppress cell-mediated immunity, although the data relating to the antibody response and B cell function in particular are less clear. For example, many studies have shown that increased secretion of stress hormones such as cortisol can alter the production of cytokines, “cytokines are important in the activation of T cells as well as in mediating the pro-inflammatory response”  Stress and the immune system: Stress and respiratory infectious illness Researchers have tested whether stress had the capacity to interfere with the body’s ability to regulate cytokine production. Normally, when a virus is detected, the body produces enough cytokines to remove the virus. However, psychologists found that stress short-circuited the body’s ability to switch off the cytokine response. Individuals who had previously experienced high stress prior to receiving the virus were found to have higher (cytokine) levels and greater symptom scores in response to the viral challenge Stress and the immune system: Stress and respiratory infectious illness Conclusion: Psychological stress does not influence upper respiratory illness by suppressing the immune system. On the contrary, stress experienced over an extended period of time results in the immune system over-responding, which in turn activates and extends the symptoms of upper respiratory infections. Stress and the immune system: Stress and wound healing In 1995, there was a study published that provided evidence that psychological stress slowed wound healing. Levels of perceived stress were the measured using questionnaires and wound was photographed every day until it completely healed. A wound was considered fully healed when it no longer foamed after hydrogen peroxide was applied! Stress and the immune system: Stress and wound healing Experiment: In the study they used a punch biopsy, 3.5 mm full thickness wound was created on the forearm, in each of the study participants. Experimental group: Participants who were caring for a relative with Alzheimer’s disease (high stress group) Control group Participants low stress group matched for age and family income Stress and the immune system: Stress and wound healing Results: The results of the study showed that complete wound healing took an average of nine days or 24 per cent longer in the caregiver group compared to the controls. They also found differences between the groups in the production of an important cytokine (interleukin-1ß) suggesting this as one of the immunological mechanisms underlying the observed effects Stress and the immune system: Stress and wound healing Next this research group investigated whether a relatively commonplace stressful event such as an examination had the potential to similarly influence wound healing. Stress and the immune system: Stress and wound healing Experiment: They placed a 3.5 mm punch biopsy wound in the mouths (i.e. on the hard palate) of a sample of dental students, once during the summer vacation and again three days before a major examination Experimental group: Participants had the biopsy in summer vacation Control group Participants had the biopsy three days before examination Stress and the immune system: Stress and wound healing Way of measuring the healing process Two independent methods assessed wound healing (daily photographs and a foaming response to hydrogen peroxide) Stress and the immune system: Stress and wound healing Results: all students took longer to heal in the examination condition compared to control conditions with complete healing taking an average of three days (or 40 per cent) longer in the examination condition. Stress and the immune system: Stress and wound healing Conclusion: These data suggest that even short-lived, predictable and relatively benign stressors can have significant consequences for wound healing. Also, these findings have important implications for understanding recovery from surgery. Evidence suggests that a more negative psychological response to surgery is associated with a slower and more complicated post-operative recovery, greater pain, longer hospital stay and worse treatment adherence Stress and the immune system: Psychological influences on recovery from surgery Psychologists suggest that psychological factors can impact wound healing, a key variable in short-term post surgical recovery, via three key pathways: 1. Emotions have direct effects on ‘stress’ hormones, and they can modulate immune function. 2. The patient’s emotional response to surgery can influence the type and amount of anaesthetic, and anaesthetics vary in their effects on the immune and endocrine system. 3. Individuals who are more anxious are also more likely to experience greater post- surgical pain, and pain can suppress immune functioning.