• Paradigm = a conceptual framework or approach within which a scientist works – that is, a set of basic assumptions, a general perspective, that defines how to conceptualize and study a subject
  • Goal: Study abnormal behaviour scientifically *try to maintain objectivity (subjective factors always interfere)
  • How to gather and interpret relevant data
  • How to think about a particular subject
  • Specifies what problems scientists will investigate and how they will do so
  • 3 main paradigms of psychology: genetic, neuroscience, and cognitive behavioural o Additional: diathesis-stress The Genetic Paradigm
  • Almost all behaviour is heritable to some degree and despite this, genes do not operate in isolation from the environment
  • “Nature via nurture”
  • Genes = carriers of genetic information passed from parents to children o We have between 20000-25000 genes *impacted by environmental influences (stress, relationships, culture)
  • Gene expression = process by which some proteins switch, or turn on and off other genes
  • Psychopathology is polygenic = several genes, operating at different times during the course of development, turning themselves on and off as they interact with a person’s environment, is the essence of genetic vulnerability
  • Relationship between genes and environment is bidirectional
  • We don’t inherit psychological disorders from our genes alone
  • We develop them through the interaction of our genes with the environment
  • Heritability = the extent to which variability in a particular behaviour (or disorder) in a population can be accounted for by genetic factors o Heritability estimates range from 0.0 to 1.0: higher number = greater heritability o Heritability is relevant only for a large population of people, not a particular individual
    • g. heritability of ADHD is .70 does not mean 70% of Jane’s ADHD is due to her genes
    • Means in a population the variation in ADHD is understood as being attributed to 70% genetic factors and 30% environmental factors
  • Shared environment factors = those things that members of a family have in common o g. family income, child-rearing practices
  • Non-shared environment “unique environment” factors = those things believed to be distinct among members of a family o g. relationships, specific events
  • Unique/non-shared experiences have much more to do with the development of psychological disorders

Behaviour Genetics

  • Behaviour genetics = the study of the degree to which genes and environmental factors influence behaviour
  • Genotype = total genetic makeup of an individual, consisting of inherited genes *unobservable o Genes switch on and off
  • Phenotype = totality of observable behavioural characteristics o Changes overtime and is the product of an interaction between the genotype and the environment Molecular Genetics
  • Molecular genetics = seeks to identify particular genes and their functions
  • Human being has 46 chromosomes (23 pairs), each made up of thousands of genes that contain DNA  Alleles = different forms of the same gene
  • Polymorphism = a difference in DNA sequence on a gene that has occurred in a population
  • DNA in genes is transcribed into RNA, sometimes translated into amino acids (to make proteins)
  • Promoter DNA is recognized by proteins called transcription factors
  • Focus on difference between people in the sequence of their genes and in the structure of their genes
  • Single nucleotide polymorphisms (SNPs) = differences between people in a single nucleotide (A, T, C, G) in the DNA sequence of a particular gene
  • Copy number variations (CNVs) = differences between people in gene structure o Can be present in a single gene or multiple genes
    • Abnormal copy of one or more sections of DNA within the gene(s) o Abnormal copies are additions/deletions
    • Found in 5% of human genome (inherited or spontaneous mutation)
    • Knockout study = specific gene is taken out of DNA in an animal to observe effect on behaviour

Gene-Environment Interactions

  • Gene-environment interaction = a given person’s sensitivity to an environmental event is influenced by genes
  • Serotonin transporter gene = gene with a polymorphism such that people have two short alleles, some have two long alleles and some have one short, one long o Combination of short-short and short-long + child maltreatment = more likely to be depressed
  • Epigenetics = study of how the environment can alter gene expression (“above”/”outside” the gene) o Marks on DNA control gene expression, the environment can influence them
    • Genes predispose individuals to seek out situations that increase the likelihood of developing a disorder

Evaluating the Genetic Paradigm

  • Direct replication = using the same measures and definitions of concepts
  • Indirect replication = including broader measures of related constructs

 

The Neuroscience Paradigm

  • Neuroscience paradigm = examines the contribution of brain structure & function to psychopathology o Mental disorders are linked to aberrant processes in the brain
  • 1) Neurons and neurotransmitters, 2) Brain structure and function, 3) Neuroendocrine system

Neurons and Neurotransmitters

  • Neuron = cell making up the nervous system, composed of (1) cell body, (2) several dendrites, (3) one or more axon, and (4) terminal buttons on the end branches of the axon
  • Nerve impulse = dendrites or cell body stimulated, travels down axon to terminal
  • Synapse = small gap between the terming ending of the sending axon and the cell membrane of the receiving neuron
  • Terminal buttons contain synaptic vesicles filled with neurotransmitters o = Chemicals that allow neurons to send a signal across the synapse to another neuron
  • When a neurotransmitter fits into receptor site of receiving neuron, message can be sent
  • Reuptake = released neurotransmitters that remain in the synapse are taken back into the presynaptic neuron
  • Key neurotransmitters in psychopathology: dopamine, serotonin, norepinephrine, gammaaminobutyric acid (GABA) o Serotonin & dopamine – depression, mania, schizophrenia o Norepinephrine – communicates with sympathetic NS, high arousal  anxiety disorders

 Serotonin, dopamine, and norepinephrine are excitatory o GABA – inhibits nerve impulses anxiety disorders

  • Agonist = drug that stimulates a particular neurotransmitter’s receptors
  • Antagonist = drug that works on a neurotransmitter’s receptors to dampen the activity of that neurotransmitter

Structure and Function of the Human Brain

  • Corpus callosum = band of nerve fibres that connects the two cerebral hemispheres, allows them to communicate
  • Gray-matter = (cortex) thin outer covering of the brain, composed of neurons (6 layers) o Gyri = ridges, Sulci = depressions between the ridges *define cerebral lobes
  • 4 main lobes: frontal (reasoning, problem solving, emotion, working memory), parietal (sensoryspatial, temporal (discrimination of sound), and occipital (vision)
  • Prefrontal cortex = very front of the cortex, helps to regulate the amygdala and is important in many different disorders
  • White matter = large tracts of myelinated fibres that connect cell bodies in the cortex with those in the spin cord and in other centres lower in the brain
  • Basal ganglia = nuclei located deep within each hemisphere, help regulate starting/stopping motor and cognitive activity
  • Ventricles = cavities in the brain filled with cerebrospinal fluid
  • Thalamus = relay station for all sensory pathways except olfactory, pass onto cortex
  • Brain stem = comprised of the pons, and the medulla oblongata, functions as a neural relay station
  • Pons = connects cerebellum with spinal cord and motor areas of cerebrum
  • Medulla oblongata = main line of traffic for tracts from spinal cord (up) and higher centres of brain (down)
  • Cerebellum = receives sensory nerves from vestibular apparatus (ear) and from muscles, tendons and joints *balance, posture, equilibrium, and smooth coordination
  • Limbic system = involved in the visceral and physical expression of emotion, and expression of appetitive and other primary drives

Anterior cingulate o Septal area o Hippocampus (memory)

  • Hypothalamus (metabolism, temperature, perspiration, blood pressure, sleep, appetite) o Amygdala (Emotion) *emotional psychological problems
    • Key brain structure for psychopathology researchers due to role in attending to emotionally salient stimuli & in emotionally relevant memories
  • Brain development begins in first trimester
  • Pruning = process of eliminating a number of synaptic connections *fewer and faster connections  Cerebellum and occipital lobe develop the quickest
  • Frontal lobe develops last The Neuroendocrine System
  • Hypothalamic-pituitary-adrenal axis (HPA) = central to the body’s response to stress, and stress figures prominently in many psyc disorders
  • Hypothalamus releases corticotropin-releasing factor (CRF) when faced with threat
  • CRF communicates with the pituitary gland, releases hormone that travels to adrenal gland
  • Adrenal cortex promotes the release of hormone cortisol – the stress hormone o Takes 20-40 minutes for cortisol release to peak
    • Takes up to an hour for cortisol levels to return to baseline
  • Autonomic nervous system (ANS) = operates very quickly, without our awareness, beyond voluntary control o Innervates the endocrine glands, the hearth, and smooth muscles

1) Sympathetic NS = prepares body for fight/flight (heart rate, dilates pupils, inhibits intestinal activity, increases electrodermal activity)

2) Parasympathetic NS = helps calm down the body o Involved in anxiety disorders (panic, PTSD)

The Immune System/Neuroendocrine System

  • Psychoneuroimmunology = studies how psychological factors impact the immune system
  • Immune system contains many cells and proteins that respond when the body is infected/invaded
  • Natural immunity = body’s first and quickest line of defense against infections microorganisms/invaders *releases cells on invaders to destroy them o Results in inflammation/swelling
  • Cytokines = help initiate bodily responses to infection (fatigue, fever, activation of HPA axis)

 Release of cytokines stimulated by activation of macrophages (cell released)  Specific immunity = cells respond more slowly to infection (lymphocytes  t-helper and b cells), involved in responding to specific pathogens or invading agents o T-helper cells promote the release of cytokines o B cells release antibodies

  • Stress directly effects the immune system (prenatal stress can even affect her offspring)
  • Interlukin-6 = cytokine that promotes inflammation in response to infection, linked to human diseases and psyc disorders (MDD)
  • Exposure to stress also slows process of wound healing
  • Risk of harmful immune response to stress increases with age

Neuroscience Approaches to Treatment

  • Use of psychoactive drugs and antidepressants has been increasing *alter neurotransmitter activity
  • Antidepressants are the 3rd most commonly prescribed medications for any type of health issue

Increase neural transmission in neurons that use serotonin as a neurotransmitter by inhibiting the reuptake of serotonin

  • Benzodiazepines used for anxiety to stimulate GABA to inhibit other neural systems that create physical symptoms of anxiety
  • Antipsychotic drugs reduce activity of neurons that use dopamine as neurotransmitter by blocking receptors

Evaluating the Neuroscience Paradigm

  • Reductionism = the view that whatever is being studied can and should be reduced to its most basic elements of constituents o g. when scientists try to reduce complex mental and emotional responses to biology
  • The whole is greater than the sum of its parts, breaking it down into pieces doesn’t mean understanding it fully

The Cognitive Behavioural Paradigm

  • Cognitive behavioural paradigm = rooted in learning principles and cognitive science

Influences from Behaviour Therapy

  • Problem behaviour is likely to continue if it is reinforced *to alter behaviour, modify consequences
  • Reinforced by 4 consequences: getting attention, escaping from tasks, generating sensory feedback, gaining access to desirable things/situations
  • Time-out = individual is sent for a period of time to a location where positive reinforcers are not available
  • Behavioural activation (BA) therapy = helping a person engage in tasks that provide an opportunity for positive reinforcement (used to treat depression)
  • In-vivo = in real life situations (type of exposure therapy) *opposite, “imaginal exposure”
  • Criticized for minimizing the importance of thinking and feeling

Cognitive Science

  • Behaviourism criticized for ignoring thoughts and emotions
  • Cognition = groups together the mental processes of perceiving, recognizing, conceiving, judging, and reasoning
  • How people structure their experiences, how they make sense of them and how they relate their current experiences to past ones
  • Schema = cognitive set used to fit new information into an organized network of already accumulated knowledge *we actively interpret new info
  • Focuses on studying human attention
  • Stroop task (colour names written in different colour ink, asked to label them as the ink colour, not the word)

The Role of the Unconscious

  • Familiarity affects judgments of stimuli
  • Implicit memory = the unconscious may reflect efficient info processing rather than being a repository for troubling material o A person can be influenced by prior learning without remembering
  • People with social anxiety and depression often have trouble with implicit memory tasks

Cognitive Behaviour Therapy

  • CBT = incorporates theory and research on cognitive processes
  • Pays attention to private events (thoughts, perceptions, judgments, self-statements)
  • Cognitive restructuring = changing a pattern of thinking *changes in thinking can change feelings, behaviour & symptoms
  • Beck’s Cognitive Therapy:
    • Cognitive therapy for depression

Based on idea that depressed mood is caused by distortions in the way people perceive life experiences *distorted thinking

  • g. focus exclusively on negative happenings, ignore positive ones o Goal: to provide people with experiences, both inside/outside the therapy room, that will alter their negative schemas, enabling them to have hope rather than despair
  • Information processing bias *attention, interpretation, and recall of negative & positive information biased in depression
  • Helps patients recognize and change maladaptive thought patterns

Evaluating the Cognitive Behavioural Paradigm

  • Some cognitive explanations do not appear to explain much
  • The thoughts are given causal status  negative thoughts cause sadness of depression
  • Focus is on current determinants of disorder o Childhood and other historical antecedents given less attention  Are distorted thoughts the cause of result of psychopathology?

Factors That Cut Across the Paradigms

  • Emotion, sociocultural, and interpersonal factors

Emotion and Psychopathology

  • Emotions influence how we respond to problems and challenges in our environment
  • Help us reorganize our thoughts and actions
  • 85% of psyc disorders include disturbances in emotional processing
  • Emotions = short-lived states, lasting for a few seconds/minutes/hours o Expressive, experiential and physiological components o Expressive/behavioural – facial expressions o Experiential/subjective – how someone reports he/she feels at a given moment o Physiological – changes in the body (autonomic NS)
  • Moods = emotional experiences that endure for a longer period of time
  • Ideal affect = the kinds of emotional states that a person ideally wants to feel

Sociocultural Factors and Psychopathology

  • Sociocultural factors: gender, culture, ethnicity, SES *may increase vulnerability to psychopathology
  • Environmental factors can trigger, exacerbate, or maintain the symptoms that make up the different disorders
  • Some disorders affect men and women differently (depression 2x common in women as men)  Poverty is a major influence on psychological disorders

Interpersonal Factors and Psychopathology

  • Quality of relationships (family, marital, social support)
  • Trauma, serious life events, and stress
  • Object relations theory = stresses the importance of long-standing patterns in close relationships, particularly within the family, that are shaped by the ways in which people think and feel o Object refers to another person (in most versions)
  • Attachment theory = the type/style of an infant’s attachment to his/her caregivers can set the stage for psychological health or problems later in life o John Bowlby & Mary Ainsworth
    • Securely attached – likely to grow up psychologically healthy o Anxiously attached – likely to experience psychological difficulties
  • Relational self = the self in relation to others o People will describe themselves differently depending on what other close relationships they have been asked to think about

 

  • Interpersonal Therapy (IPT):
    • IPT = emphasizes the importance of current relationships in a person’s life and how problems in these relationships can contribute to psychological symptoms
    • 1) Unresolved grief o 2) Role transitions o 3) Role disputes
    • 4) Interpersonal/social deficits Diathesis-Stress: An Integrative Paradigm
  • Most disorders are likely to develop through an interaction of neurobiological and environmental factors
  • Diathesis-stress paradigm = integrative paradigm that links genetic, neurobiological, psychological and environmental factors *multiple causal factors
  • Introduced as a way to account for multiple causes of schizophrenia o Diathesis (disease), stress (environment/life disturbances **may occur at any point after conception)
    • Diathesis = predisposition towards illness/any characteristics a person has that increases his/her chance of developing a disorder
  • Both diathesis and stress are necessary in the development of disorders

Psychopathology is unlikely to result from the impact of any single factor