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15: February Biopsychosocial Model Biopsychosocial unified approach - no single aspect can fully explain the complexity of psychological disorders - each causal factor is interacting with the other How did these factors interact to produce THIS disorder in THIS person at THIS time? Example: Judy, a 16-year-old, was referred to an anxiety clinic after increasing episodes of fainting. About 2 years earlier, in her biology class, the teacher showed a graphic film of a frog dissection, with vivid images of blood, tissue, and muscle. About halfway through, Judy felt lightheaded and left the room. But the images didnt leave her. She continued to be bothered by them and occasionally felt queasy. She began to avoid situation where she might see blood or injury. She stopped looking at magazines that might have gory pictures, and found it difficult to look at raw meat, or even Band-Aids. It got so ba that she felt lightheaded when her friend exclaimed, Cut it out! She fainted anytime she unavoidably encountered blood. Each time, her parents or friends rushed to her side, but were unable to help. By the time of referral, Judy was fainting 5-10 times a week, often in class. Because her physician could find nothing wrong with her, Judys principal concluded that she was being manipulative and suspended her from school, even though she was an honors student. Multiple, interacting influences that contribute to Judys phobia: Psychological - classical conditioning and stimulus generalization - generalizes her reaction to a US to include anything related to the UShas a conditioned response to anything related to blood - negative thoughts and avoidance maintain fear (negative reinforcement) - she cannot habituate to her fear, so her conditioned response is maintained - fear triggers more intense physiological response Cognitive - a cognitive psychologist would look for some sort of irrational interpretations (such as Judys interpretation of band-aids) - Ellis would say that Judy is having catastrophic thoughts (like Blood will cause me to faint and hit my head and die or It will cause terrible social humiliation) - becomes a self-fulfilling prophecy Psychodynamic - repression or denial of a previous traumatic event, such as a bloody car accident - her mind is naturally protecting her by fainting, so she can avoid dealing with the trauma Social - social attention (positive reinforcer) may increase symptoms, because she likes the attention - rejection and adversity can worsen mental disorders Biological - oversensitive sinoaortic baroreflex archow the body reacts to elevations in blood pressure - the experience of disgust causes her to have a sudden increase in blood pressure, and her body overcompensates activating the parasympathetic nervous system to maintain homeostasisthe overcompensation leads to less blood flow to the brain, so she faints - this oversensitivity seems to be inherited - vasovagal syncope - if medicine solves the problem, then Judy will become dependent on medicineshe never cognitively learns that panic attacks arent going to hurt her - she will relapse if she goes off the medicine - anxiety medications are usually addictive - this is actually avoidance Genetic contributions to psychopathology - our genes provide boundaries to our development February 15: Biopsychosocial Model - ex. 2 people have predispositions for being tall, but we know that malnutrition will cause those people to not grow as tall as they could have - ex. we know that even identical twins (share 100% genes) dont look exactly the same - vulnerabilities to mental disorders are almost always polygenic = caused by many genes - genetic factors account for less than of the explanation of mental disorder - ex. if one identical twin has schizophrenia, there is less than 50% that the other twin will develop schizophrenia as welland schizophrenia is highly inheritable - genetic contributions to mental disorders need to be studies in interaction with the environment - genotypein any one cell, only some of the genes are expressed - phenotype = our observable, unique combination of expressed genes - ex. identical twins have the same genotypes, but different phenotypes Diathesis-stress model Inherited hits (the diathesis) + environmental hits = expressed disease - a genetic predisposition for a disorder is inherited, but it isnt activated unless something in the environment (like stress) turns it on Ex. Family history of Vasovagal Syncope + exposure to dissection OR puberty = blood-injection phobia - puberty is important because many stressful social, cognitive, and physical changes occur at that time - most psychological disorders experience their onset around puberty or adolescence - recent evidence suggests this additive model may be overly simplistic The revised diathesis-stress model - incorporates the biopsychosocial model - only one of the 3 diathesises is necessary Ex. Say that someone has developed a very repressive coping style and deny/avoid any negative emotions. They learned this at home, because anytime they expressed distress as a child, they were beaten. Their repressive coping is okay if they never experience any life stressorsbut the majority of people are exposed to a traumatic event in their lifetime. Experiencing a traumatic event, in combination with his repressive coping style, could trigger a disorder. Reciprocal gene-environment model - genes and the environment affect each other in a bidirectional way to lead to the development of a disorder Genotype-environment correlations = when a genotype shapes the environmental experience that an individual has Example: Jerry had a genetic predisposition to aggressive behavior. His frequent fist fights at school resulted in peer rejection in the early grades. Such rejection led Jerry to go on to associate with similarly aggressive and delinquent peers in later grades. Increased exposure to peers with delinquent behaviors eventually influenced Jerry to develop a full-blown pattern of delinquency in adolescence. - in adulthood, Jerry may further develop full-blown antisocial personality disorder - because of his peers responses to his predisposition, Jerry had a reaction that led to him being more exposed to his predisposition - this doesnt always have to be negativea child may like the responses they get Ex. An extroverted child seeks the company of others and enhances their own tendencies to be social because their environment was influenced by their predisposition to be social. Genotype-environment interactions - people with different genotypes may be differentially susceptible to their environments, which influences them to develop a disorder February 15: Biopsychosocial Caspis Model Example: research on the serotonin-transporter gene - serotonin neurotransmitters are involved with depression - a gene has been identified that has 2 different alleleslong (l) or short (s) - studies on animals suggest that those with ss tend to have an increased risk for developing depression in response to stress - Caspi studies humans and their environments over many years to see the effects of this gene - the effect of the short alleles depended on the number of stressful events that occurred - those with ss were twice as likely to develop a major depressive disorder after 4 or more major life stressors as compared to those with llthose with ls fell somewhere in between - those with ss and severe maltreatment during childhood were also twice as likely to develop a major depressive disorder as compared to those with ss and a good childhood Beyond genetics: other biological influences Brain structure and function - the first disorders recognized as having a biological component were those associated with brain damage - ex. Phineas Gages prefrontal lobe was destroyed, so his higher cognitive functions (like social etiquette) were affected - most mental disorders are not caused by brain damage, but by hormonal and neurotransmitter abnormalities Hormonal abnormalities - hormones are transported all over our bodies by hormonal glands that interact with each other - ex. the hypothalamic-pituitary-adrenal-crotical axis (HPA axis) is important in our stress response Neurotransmitter abnormalities - has made the largest impact in biological influences and psychiatry Neurotransmitter abnormalities Neurotransmission - neurons (nerve cells) communicate via neurotransmitters - a neuron releases a neurotransmitter into the synaptic gap, where it is picked up by another neuron gives off an electrical charge - depending on the level and type of neurotransmitter, the neuron will either fire or not firecan have an excitory or an inhibitory response on the next neuron - this is an all-or-nothing response - afterwards, the neurotransmitters dont just float around in the synapse - the remaining neurotransmitters are deactivated through reuptake = the presynaptic neuron takes back the neurotransmitters through its axon terminal - or, the presynaptic neuron releases an enzyme into the synapse to degrade the neurotransmitters February 15: Biopsychosocial Model - if the neurotransmitters float around in the synapse for too long, they may cause an unintended response in the postsynaptic neuron Problems arise when - excess production and release into the synapses - caused by either too little or too much of either reuptake or degradation - dysfunction in neurotransmitter deactivation (such as problems with reuptake) - problems with receptors in the postsynaptic neuron - receptors might be too sensitive or not sensitive enough 4 neurotransmitters are most associated with psychopathology: 1. Serotonin - important in the regulation of mood, emotions, and impulses - important in the way that we think and process info from our environment - implicated in emotional depression and anxiety disorders - in some areas, too little serotonin causes depressionin other areas, too much serotonin causes depression - we originally thought a lack of serotonin was associated with depression - amino-oxidase inhibits serotonin to reduce symptoms of depression 2. Norepinephrine (similar to adrenaline) - responsible for emergency responses that cause the fight-or-flight response) - helps the body respond to a stressful or dangerous situation - implicated in anxiety and depression - important in attention, orienting, and basic motives - cocaine and amphetamines prolong the action of norepinephrine in the synapse, so people continue to feel a high and feel on edge and full of energy - a lack of norepinephrine, therefore, is associated with depression and a lack of energy 3. GABA (gamma aminobutyric acid) - an inhibitory neurotransmitter - involved in reducing anxiety and mania - reduces excitement caused by the increased firing of neurons (this increased firing leads us to have strong reactions) - present in anticonvulsive drugs for seizures - present in alcohol, which makes us sedated 4. Dopamine - regulates reinforcments and rewards - important in cognitive processing, muscle systems, and pleasure systems - ADD is helped by increasing dopamine levels Impact of changing dopamine levels Too much dopamine hallucinations, paranoia What increases dopamine? schizophrenia, cocaine, speed, nicotine, Ritalin Too little dopamine slow movements, trouble initiating movements, tremors, low mood - looks like Parkinsons disease Drug therapies and mechanisms Drug class Antidepressants Symptoms targeted Depression Examples MAOIs Tricyclics SSRIs SNRIs NDRIs Hypothesized action INC serotonin INC norepinephrine INC dopamine February 15: Biopsychosocial Model Mood stabilizers Mania Depression Lithium Anticonvulsants Anxiolytics Anxiety Insomnia Neuroleptics Psychosis Benzodiazapines SSRIs Typicals Haldol Atypicals Zyprexa INC serotonin DEC norepinephrine INC GABA ? Glutamate INC serotonin INC GABA DEC dopamine Antidepressants MAOIs if you eat too much dairy, you get dangerous side effects (like a spike in blood pressure) Tricyclics target all 3 neurotransmitters, so it has strong side effects like blurred vision and risk of overdose SSRIs, SNRIs, and NDRIs most modern, as effective as tricyclics but have fewer side effects because they one target one or 2 neurotransmitters Mood stabilizers - usually target mania Lithium a natural substance that we accidentally learned is helpful in regulating mood - were uncertain about the mechanisms of how lithium works - an overdose is possible and its difficult to maintain a balance of lithium in the body - those taking lithium must have the lithium levels checked frequently - kidney malfunction is a side effect of having weird levels of lithium Anxiolytics - associated with relaxation and sedation - used as a sleep agent for insomnia SSRIs also helpful for treating anxiety, which shows the comorbidity between anxiety and depression; also help with bulimia Neuroleptics - antipsychotics Typicals early antipsychotic that reduced dopamine and had severe side effects Atypicals more modern and reduced side effects (especially one condition in which the patient experienced uncontrollable facial and tongue movements) Why do you think the idea of a chemical imbalance causing mental disorders has become so popular in our culture? - led to a lot of revolutionized medical treatments - for many of the disorders, drugs only help some of the symptoms but not all of them ... 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