PS280-Z Lecture 4 – Thursday July 18th, 2013.docx

th PS280-Z Lecture 4 – Thursday July 18 , 2013 Theoretical Perspectives on Abnormal Behaviour What is a Theory? - A way of intepreting, viewing, or explaining a behaviour - Direct research and guide decisions people make (when they do diagnosis) - They are a means of providig improvement - Like a lens that is used to see or understand a phenomenon in a particular way - Based on principles, rules, norms, beliefs, and/or observations - Can be classified according to their level of explanation Naturalistic Theories - Consider abnormal behaviour to be the result of either biological causes of environmental factors The Biological Perspective - Researchers and clinicians look for a biological basis for disordered behaviour - Relies on a classification system that identifies the person as being disordered The Environmental Perspective - Researches and clinicians look for environmental events that shape behaviour o Can include things like viral infections which can causes changes - Treatment approaches involve manipulating or changing the environment or modifying the individual‟s perceptions of the environment - Treatment does not necessarily eclude using biological treatments such as medication Single Factor Explanations - One factor is responsible for causing the disorder o For example – a traumatic experience causing a problem (very rare unless we are talking about PTSD) - Limited in their power to explain behaviour or to suggest appropriate treatment approaches - Exist but are rare in psychology, though common in popular culture - Even conditioning models look at more than one factor - However, many of the psychoanalytic explanations are single factor Interactionist Explanations (Multi-dimensional models) - Most current theories consider multiple factors (biological, psychological, and/or social) - Cognitive, biological, learning, emotional, social, cultural facotrs interact in complex ways to cause and maintain behaviour - Some are interdisciplinary Diathesis-stress Models - The diathesis involves a pre-existing vulnerability - Could be genetic - Could also be due to negative early childhood experiences - Later the disorder may be triggered by stress o Ex – person has a genetic predisposition toward depression and then when they are older and something happens to them, they would get devastated and become depressed  Children who are premature are more likely to be abused Reciprocal Gene-Environmental Model - Some people have genetically determined risk to create certain kinds of environments that trigger genetic vulnerabilities - May explain depression or divorce Stress Generation Model of Depression - Came from observation that depression is associated with negative life events - Some people who have repeated episodes of depression have more negative events in the interpersonal realm What do researchers look for in a theory? 1. Practical value o Theories generate research that increases knowledge and new approaches for treatment 2. Parsimony o The theory integrates most of what is currently known about the phenomenon or problem in the simplest way possible 3. Heuristic value o Theorists stimulate further research and ideas 4. Precision and Testability o The theory can be translated into concrete terms The Search for Causes of Abnormal Behaviour - We want to: o Explain the etiology or causes or origings of the problem o Identify the factors that maintain the behaviour o Predict the course of the disorder o Design effective treatments Variety of Theories - Many different theories about mental disorders have been proposed - Biological psychodynamic, learning (which includes behavioural or cognitive-behavioural theories), cognitive, humanistic-experiential, and socio-cultural - The interactionist approach is becoming increasingly popular (biological, behavioural, and environmental systems operate as a whole system) - We often overlook social, culture, socio-economic factors, racism, etc Reductionism - Faulty claim that the action of the entire system is determined or caused by one or other of the parts - Human behaviour is the product of the interaction of many factors Biological Determinism or Reductionism - Very common - Focus on biological factors without considering the role of environmental factors - In an extreme form, it assumes that if the causes of biological, psychological, and environmental interventions will not address the problem Psychological & Environmental Interventions have a Significant Impact on Disorders w/ Biological Determinants - Phenylketonuria (PKU): enzyme deficiency due to abnormality in chromosome 12 - Altering the environment (diet) makes enormous difference Environment and Cultural Determinism - Denies the influence of biological factors - Therapy for depresion in hypothyroidism - Psychotherapy for those with gene for Huntington‟s chorea o Need all the help they can get for what is to come but it cannot change the ultimate outcome The Biological Paradigm - The brain and the mind are one - All thoughts, feelings, and actions are related to CNS activities - The biological model of abnormality took off with the discovery that untreated syphilis causes mental illness - Biological models of abnormality take different forms - Structural damage to the brain - Neurotransmitter system is defective - Hormones or the autonomic nervous system - Defective genes The Brain (Central Nervous System) - 100,00 billion+ neurons - Weighs about 3 pounds - 2 hemispheres connected by the corpus callosum Causes of Brain Damage - Head injuries, concussions o Even having one concussion can raise your risks of having Alzheimer‟s when you‟re older - Tumours, strokes - Diseases such as syphilis, HIV - Damage due to excessive alcohol use, drug abuse Fetal Alcohol Spectrum Disorder (FASD) - 100% preventable - Under-diagnosed - There is no known safe level of alcohol consumption at any stage of pregnancy - Effects may not show up until adolescence, so research that follows children for a few years is inadequate - Females who are sexually active, and who consume alcohol, should use highly effective birth control or abstain from alcohol all together Transcranial Magnetic Stimulation (TMS) - Some people are treated for depression with brain stimulation - TMS involves giving magnetic stimulation in a way that leads to rapidly changing magnetic fields - Still experimental - Researchers can temporarily turn off areas of the brain with this Prosopagnosia - Face blindness - Can be caused by head injury, right temporal lobe - Also developmental, believed to be relatively common in people with Asperger‟s or autism - Prevalence may be as high as 2% Synesthesia (Crossed Scenes) - Name means to „perceive together‟ - Women experience it more often than men - Most common form involves seeing colours when exposed to numbers, letters, and words - Perhaps increased wiring between neighbouring areas o Too much going on between brain areas that normally do not share much information - Or there is a shortage of inhibition between the neighouring brain areas Capgras Syndrome - Right frontal lobe damage - Believe that a loved one has been replaced by an imposted – such as Tony Rosato - Somatic marker hypothesis o Idea that the bodily (or somatic) emotional component of thought is a necessary part of problem solving and decision making Head Injuries - Right side of the brain seems to be more involved in negative emotion, so when it is injured, people are more likely to develop mania - Left side of the brain seems to be more involved in positive emotion, when left side is active, people tend to be happier Frontal Lobe Damage - Case of Phineas Gage o 1700 or 1800s – involved in an accident where a spike pierced his skull and came out of the other side – he survived but he became profane, difficult, sexually inappropriate, etc - Case of Marcus Dementia - Ongoing brain degeneration - Complex causes - In some cases genetic - Associated with head injuries, e.g. loss of oxygen or concussions - Dementia is more common in people who have had head injuries, but also more common in people who have had multiple episodes of depression - 50% of people get it over the age of 90 (the older you will be when you get it) - The more you use your mind and stimulate yourself throughout your life, the more likely you will get it or not at all Alzheimer‟s and Parkinson‟s - Parkinson‟s is genetic in some cases, but also associated with exposure to contaminants, such as manganese (high in welders), pesticides, solvents, mercury - Parkinsons‟ causes dementia in early or late stages Biochemical Theories of Abnormality - Neurotransmitter inblanaces are associated with mental disorders such as depression, schizophrenia, Alzheimer‟s, Parkinson‟s, and other disorders - There are different types of serotonin and dopamine receptor sites Neurotransmitter Malfaunctions - Too much or too little of the neurotransmitter is produced or relearsed - Too much or too little of the deactivating substance in the synapse - Reuptake process is too rapid or too slow - Too many or too few receptors on the receiving neuron - Imbalance of different neurotransmitters Dopamine Imbalance - Deficienty of dopamine in Parkinson‟s disease - In schizophrenia, there is excessive dopamine or dopamine sensitivity - Effects of altering dopamine levels or of Parkinson‟s - Reward deficiency syndrome - Leads to outcomes such as compulsive overeating, smoking, pathological gambiling, ADHD o Also seen in people with Parkinson‟s Serotonin - Helps sleep, decreases anxiety, improves mood - One theory that having abnormally long or short alleles for serotonin transporter genes is associated with psychopathy - For those with low SES, people have abnormally long alleles back empathy, but are not impulsive; this is not the case for those with high SES - Those with short alleles are impulsive and lack empathy whatever their SES Other Neurotransmitters - Norepinephrine o Increases the persons level of arousal and alertness o Having low amounts are related to depression and feeling tired - Acetylcholine (Ach) o People with Alzhiemer‟s have a defecit of Ach o Brain blood barrier – lots of medications will not have effects on the brain - GABA (can be bought over the counter) o Involved in relaxation o People with low amounts tend to be more anxious Autonomic Nervous System - Not under your direct control – they happen without your conscious knowing - During stress, sympathetic system readies bodies for action - Parasympathetic system helps body to recover after stress reaction; slows processes - Anxiety disorders associated with overly active sympathetic nervous system o As if they are in a constant state of over arousal Endocrine System - Hormones - Play