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Chapter 3

Chapter 3. Models of Abnormality. Models of Abnormality. In science, the perspectives used to explain phenomena are known as models or paradigms Each provides a set of assumptions and concepts that help us explain and interpret observations A school of thought

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Chapter 3

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  1. Chapter 3 Models of Abnormality

  2. Models of Abnormality • In science, the perspectives used to explain phenomena are known as models or paradigms • Each provides a set of assumptions and concepts that help us explain and interpret observations • A school of thought • Helpful because they spell out basic assumptions and set guidelines for investigation • They influence what investigators observe, the questions they ask, the information they seek, and their interpretation of that information

  3. Models of Abnormality • Historically, clinical scientists of a given time and place agreed on a single model of abnormality – a model greatly influenced by cultural beliefs • Currently, there are several competing models of abnormality • Why? Each model focuses on one aspect of human functioning and no single model can explain all aspects of abnormality

  4. The Biological Model • Takes a medical perspective • Main focus is that psychological abnormality is an illness brought about by malfunctioning parts of the organism • Typically focused on the brain

  5. Four factors that are associated with this approach 1. Influence of germs 2. Genetic links 3. Biochemical changes 4. Neuroanatomical changes

  6. How Do Biological Theorists Explain Abnormal Behavior? • Brain anatomy • The brain is composed of ~100 billion nerve cells (called neurons) and thousands of billions of support cells (called glia) • Within the brain, large groups of neurons form distinct areas called brain regions

  7. How Do Biological Theorists Explain Abnormal Behavior? • Brain anatomy and abnormal behavior • Clinical researchers have found connections between certain psychological disorders and problems in specific brain areas • Example: Huntington’s disease & basal ganglia (forebrain)

  8. How Do Biological Theorists Explain Abnormal Behavior? • Brain chemistry • Information spreads throughout the brain in the form of electrical impulses that travel from one neuron to one (or more) other neurons • An impulse is first received at a neuron’s dendrites, travels down the axon, and is transmitted to other neurons through the nerve endings

  9. Brain Anatomy and Abnormal Behavior The brain is composed of ~ 100 billion nerve cells or neurons and thousands of billions of support cells or glia • Large groups of neurons form brain regions: • Distinct areas that control important functions • Clinical researchers have discovered connections between certain psychological disorders and specific areas • Huntington’s Disease – loss of cells in the basal ganglia (forebrain)

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  11. How Do Biological Theorists Explain Abnormal Behavior? • Brain chemistry • Neurons don’t touch; they are separated by a space (the synapse), across which a message moves • When an electrical impulse reaches a nerve ending, the nerve ending is stimulated to release a chemical called a neurotransmitter (NT) • Some NTs tell receiving neurons to “fire;” other NTs tell receiving neurons to stop firing

  12. How Do Biological Theorists Explain Abnormal Behavior? • Brain chemistry • Researchers have identified dozens of NTs • Examples: serotonin, dopamine, and GABA • Studies indicate that abnormal activity in certain NTs can lead to specific mental disorders • Examples: depression (serotonin and norepinephrine) and anxiety (GABA)

  13. Recent studies have focused on the role of NT in their impact on behavior Acetylcholine - first known NT. it is involved with transmission to muscles. Dopamine - regulates motor behavior, excess dopamine is thought to be a cause of schizophrenia. It is developed in the mid-brain above the pons.

  14. Enkephalines - opiate receptors, affected by opium derivatives, may be able to produce natural highs. May be the source of runners high. GABA - gamma-amino-butyric-acid, an inhibitory NT. Histamines - allergic reactions Norephinephrine - acts on autonomic nervous system to produce energizing responses. Serotonin - transmissions within the brain, may play a role in depression.

  15. How Do Biological Theorists Explain Abnormal Behavior? • Brain chemistry • Additionally, researchers have learned that mental disorders are sometimes related to abnormal chemical activity in the endocrine system • Hormone release, triggered by a variety of factors, propels body organs into action. Abnormal secretions have been linked to psychological disorders • Example: cortisol release is related to anxiety and mood disorders

  16. How Do Biological Theorists Explain Abnormal Behavior? • Sources of biological abnormalities – Genetics • Humans have 23 pairs of chromosomes, each with numerous genes that control the characteristics and traits a person inherits • Studies suggest that inheritance plays a part in mood disorders, schizophrenia, mental retardation, Alzheimer’s disease, and other mental disorders • Aren’t able (yet) to identify specific genes • Don’t know the extent to which genetic factors contribute to disorders • Seems no SINGLE gene is responsible for a particular behavior or disorder

  17. Causes of Biological Abnormalities Genetic Inheritance • Each cell in the human body contains 23 pairs of chromosomes • Inherited from a person’s parents • Cells contain between 30,000 - 40,000 genes that control the characteristics and traits being inherited • Studies suggest inheritance plays a role in: • Mood disorders • Schizophrenia • Mental retardation • Alzheimer’s disease • Genes combine to help produce our functional and dysfunctional actions • In most cases no single geneis responsible for particular behavior or mental disorder • Human Gnome Project • Research to identify which genes help cause various human disorders

  18. Behavior genetics - examines influence of genes on behavior • Genotype - a unique genetic code, a persons genetic makeup • Phenotype - behavioral expression of the interaction of genotype and the environment. Often it is difficult to determine which is predominant --> nature vs. nurture controversy.

  19. Twin studies are often used to study genetic/environment interactions Two types of twins • Monozygotic (MZ) - identical twins, develop from 1 fertilized egg. They have the exact same genotype. Do they have the same phenotype? • Dizygotic (DZ) - fraternal twins, develop from 2 eggs fertilized by 2 different sperm. They have less than 50% of their genes in common.

  20. Studies of Concordance - when twins develop the same disorder Research studies use groups of MZ twins that are compared to DZ twins. If the concordance rate is higher in MZ (3:1) than in DZ twins, then it is likely their is a genetic connection for that disease. If their is little concordance in the MZ twins it may be due to interaction with the environment or some other cause.

  21. Recent studies of MZ twins have found high concordance rates in anxiety reactions alcoholism schizophrenia depression

  22. How Do Biological Theorists Explain Abnormal Behavior? • Sources of biological abnormalities – Evolution • Genes that contribute to mental disorders are viewed as unfortunate occurrences: • May be mutations • May be inherited after a mutation in the family line • Evolutionary theorists argue that we can best understand abnormality by examining the millions of years of human evolution • Looking at a combination of adaptive behaviors of the past, genes, and the interaction between genes and current environmental events • This model has been criticized and remains controversial

  23. How Do Biological Theorists Explain Abnormal Behavior? • Sources of biological abnormalities – Viral infections • Infection provides another possible source of abnormal brain structure or biochemical dysfunction • Example: schizophrenia and prenatal viral exposure • Interest in viral explanations of psychological disorders has been growing in the past decade • Example: anxiety and mood disorders

  24. Biological Treatments • Biological practitioners attempt to pinpoint the physical source of dysfunction to determine the course of treatment • Three types of biological treatment: • Drug therapy • Electroconvulsive therapy (ECT) • Psychosurgery

  25. Biological Treatments • Drug therapy: • 1950s = advent of psychotropic medications • Changed outlook for a number of mental disorders • Four groups of drugs: • Antianxiety drugs (anxiolytics; tranquilizers) • Antidepressant drugs • Antibipolar drugs (mood stabilizers) • Antipsychotic drugs

  26. Biological Treatments • Electroconvulsive therapy (ECT): • Currently experiencing a revival • Used for depression when drugs and other therapies have failed • In 60% of cases, ECT can lift symptoms within a few weeks

  27. Biological Treatments • Psychosurgery (or neurosurgery): • Historical roots in trephination • 1930s = first lobotomy • Much more precise than in the past • Considered experimental and used only in extreme cases

  28. Measuring the brain Other forms of brain study are needed to study brain function and structure. • early methods - dissections • advanced CT and MRI scans study brain structure. Pet scans study brain function

  29. CT (CAT) scan - computerized axial tomography, passes gamma-rays through cross-sections of the intact brain and measures radioactivity on the other side. By locating differences in tissue density, tumors can be located.

  30. MRI - Nuclear magnetic resonance imaging. More precise and detailed than CT. Enclosed in a magnetic field, radio waves are used to locate abnormalities in tissue. Very accurate, excellent details. Can be used from different viewpoints to create different perspectives for different dimensional views.

  31. PET - Positron Emission Tomography - (a measure of brain activity) observes brain activity by monitoring an injected radioactive tracer substance moving though blood vessels of the brain. Studies have shown that schizophrenics have greater blood flow to the left hemisphere of the brain than the rt. hemi. The more severe the schiz. the greater the difference in left/right blood flow. One conclusion has been drawn, Schiz. is the result of left hemi. damage, greater blood flow is the bodies attempt to compensate.

  32. Weaknesses: Can limit rather than enhance our understanding Too simplistic Evidence is incomplete or inconclusive Treatments produce significant undesirable (negative) effects Strengths: Enjoys considerable respect in the field Fruitful Creates new therapies Suggests new avenues of research Assessing the Biological Model

  33. The Psychodynamic Model • Oldest and most famous psychological model • Based on belief that a person’s behavior (whether normal or abnormal) is determined largely by underlying dynamic psychological forces of which she or he is not aware • Abnormal symptoms are the result of conflict among these forces • Father of psychodynamic theory and psychoanalytic therapy: • Sigmund Freud (1856 – 1939)

  34. First hypothesis - became known as depth psychology Two basic principles of this theory I. Conflict causes anxiety II. The mind works on 2 levels 1. Conscious mind, awareness, here and now 2. Unconscious mind, has 2 levels identifiable by the retrievability of memories What evidence do we have that the unconscious exists?

  35. Second Hypothesis Focus is on mental structures and instincts Behavior is a product of 3 mental structures Id Ego Superego

  36. How Did Freud Explain Normal and Abnormal Functioning? • Abnormal behavior is caused by three UNCONSCIOUS forces: • Id – guided by the Pleasure Principle • Ego – the reality principle • Superego – our values and ideals

  37. The Id • Psychological force that produces instinctual needs, drives, and impulses • Pleasure principle • Always seeks gratification • All id instincts tend to be sexual in nature • A person’s libido fuels the id • Instinctual needs, drives, & impulses • Sexual; fueled by libido (sexual energy)

  38. 2. Ego Function • Ego – guided by the Reality Principle • Seeks gratification but guides us to know when we can & can’t express our wishes • Ego defense mechanisms protect us from anxiety

  39. The Ego • Psychological force that employs reason • Once we realize our environment will not meet every instinctual need, part of the id separates into the ego • Unconsciously seeks gratification • Reality principle • Knowledge that it can be unacceptable to express our id impulses outright • The ego guides us to know when we can and cannot express impulses • Ego Defense Mechanisms • Basic strategies to control unacceptable id impulses • Repression – the most basic • prevents these impulses from reaching consciousness

  40. The Superego • The psychological force that represents a person’s values and ideas • Grows out of the ego • Development of a conscious • Based on feelings of doing good vs. guilt • As we learn that many of our id impulses are unacceptable, we unconsciously adopt certain values

  41. How Did Freud Explain Normal and Abnormal Functioning? • These three parts of the personality are often in conflict • A healthy personality is one in which compromise exists among the three forces • If the id, ego, and superego are in excessive conflict, the person’s behavior may show signs of dysfunction

  42. How Did Freud Explain Normal and Abnormal Functioning? • Developmental stages • Freud proposed that at each stage of development, new events and pressures require adjustment in the id, ego, and superego • If successful → personal growth • If unsuccessful → fixation at an early developmental stage, leading to psychological abnormality • Because parents are the key figures in early life, they are often seen as the cause of improper development

  43. How Did Freud Explain Normal and Abnormal Functioning? • Developmental stages • Oral (0 to 18 months of age) • Anal (18 months to 3 years of age) • Phallic (3 to 5 years of age) • Latency (5 to 12 years of age) • Genital (12 years of age to adulthood)

  44. How Do Other Psychodynamic Explanations Differ from Freud’s? • Although current models deviate from Freud’s in important ways, each retains the belief that human functioning is shaped by dynamic (interacting) forces: • Ego theorists • Emphasize the role of the ego; consider it independent • Self theorists • Emphasize the unified personality over any one component • Object-relations theorists • Emphasize the human need for interpersonal relationships

  45. Psychodynamic Therapies • Range from Freudian psychoanalysis to more modern therapies • All seek to uncover past trauma and inner conflicts • Understanding early life experience critically important • Therapist acts as “subtle guide”

  46. Psychodynamic Therapies • Utilize various techniques: • Free association • Therapist interpretation • Resistance • Transference • Dream interpretation • Catharsis • Working through

  47. Psychodynamic Therapies • Contemporary trends: • Short-term psychodynamic therapies • Relational psychoanalytic therapy

  48. Strengths: First to recognize importance of psychological theories & treatment Saw internal conflict as important source of psychological health and abnormality First to apply theory and techniques systematically to treatment – monumental impact on the field Weaknesses: Unsupported ideas; difficult to research Non-observable Inaccessible to human subject (unconscious) Assessing the Psychodynamic Model

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