clinical psychology

1. Causes of Mental IllnessCauses of Mental Illness
Lecture 13Lecture 13

2.  The precise causes (etiology) of most mentalThe precise causes (etiology) of most mental
disorders are not knowndisorders are not known
 But the broad forces that shape themBut the broad forces that shape them areare
known: these areknown: these are biologicalbiological,, psychologicalpsychological,,
andand social/culturalsocial/cultural factors.factors.
 These causes are generally viewed as aThese causes are generally viewed as a
product of theproduct of the interactioninteraction between biological,between biological,
psychological, and sociocultural factors.psychological, and sociocultural factors.

3.  The brain and behavior are inextricably linkedThe brain and behavior are inextricably linked
 Psychological and sociocultural phenomenaPsychological and sociocultural phenomena
involve structural changes in the neurons andinvolve structural changes in the neurons and
neuronal circuitsneuronal circuits
 Psychological and sociocultural events andPsychological and sociocultural events and
phenomena continue to have meaning forphenomena continue to have meaning for
mental health and mental illness.mental health and mental illness.

4. Bio-psycho-social Model ofBio-psycho-social Model of
DiseaseDisease
 George L. Engel, (1977)George L. Engel, (1977)
 The model lacksThe model lacks sufficient specificitysufficient specificity to maketo make
cause- and- effect predictionscause- and- effect predictions
 The model takes a broad view that biologicalThe model takes a broad view that biological
factors are not the only cause of mental illness,factors are not the only cause of mental illness,
environmental and psychological factors areenvironmental and psychological factors are
also important.also important.

5.  The relative importance or role of any one factor inThe relative importance or role of any one factor in
causation often varies.causation often varies.
 For example, schizophrenia is linked strongly toFor example, schizophrenia is linked strongly to
genetic factorsgenetic factors
 But psycho-social factors modify expression andBut psycho-social factors modify expression and
outcome of such disorders.outcome of such disorders.
 Likewise, some mental disorders such as (PTSD), areLikewise, some mental disorders such as (PTSD), are
mostly environmental in naturemostly environmental in nature
 But pre-trauma vulnerability also determines the onsetBut pre-trauma vulnerability also determines the onset
of PTSDof PTSD
 Similarly depression can be caused by stressful lifeSimilarly depression can be caused by stressful life
events as well as due to genetic predispositionevents as well as due to genetic predisposition

6. Understanding Correlation,Understanding Correlation,
Causation, and ConsequencesCausation, and Consequences
 Three terms must be distinguished in the etiology ofThree terms must be distinguished in the etiology of
mental illness:mental illness:
 correlationcorrelation,, causationcausation, and, and consequencesconsequences
 A biological change in the brain could be a correlate, aA biological change in the brain could be a correlate, a
cause of, or an effect of the mental disorder.cause of, or an effect of the mental disorder.
 Researchers usually start by noticing correlations toResearchers usually start by noticing correlations to
find out “risk factors”find out “risk factors”
 Risk factors are biological, psychological, or socio-Risk factors are biological, psychological, or socio-
cultural variables that increase the probability forcultural variables that increase the probability for
developing a disorder and antedate its onset.developing a disorder and antedate its onset.

7.  EstablishingEstablishing causationcausation of mental health andof mental health and
mental illness is extremely difficult becausemental illness is extremely difficult because
experiments with humans may be limited.experiments with humans may be limited.
 Thus most information comes from correlationalThus most information comes from correlational
research.research.
 Correlational research must confirm evidenceCorrelational research must confirm evidence
from biological & chemical findings in animalfrom biological & chemical findings in animal
models.models.

8.  Consequences are defined as the laterConsequences are defined as the later
outcomes of a disorder.outcomes of a disorder.
 For example, in depression : increasedFor example, in depression : increased
mortality from either suicide or medical illnessmortality from either suicide or medical illness
 Thus, the bio-psycho-social model holds thatThus, the bio-psycho-social model holds that
biological, psychological, or social factors maybiological, psychological, or social factors may
bebe causescauses,, correlatescorrelates, and/or, and/or consequencesconsequences
in relation to mental health and mental illness.in relation to mental health and mental illness.

9. Biological Influences on MentalBiological Influences on Mental
Health and Mental IllnessHealth and Mental Illness
 Biological and physical influences on mentalBiological and physical influences on mental
health and mental illness are far reaching.health and mental illness are far reaching.
 Categories include genes, infections, physicalCategories include genes, infections, physical
trauma, nutrition, hormones, and toxins etc.trauma, nutrition, hormones, and toxins etc.

10. The Genetics of Behavior andThe Genetics of Behavior and
Mental IllnessMental Illness
 Genes influence behavior: an established factGenes influence behavior: an established fact
 Mostly defects inMostly defects in multiplemultiple genes are the causegenes are the cause
 The human genome project : will provide helpThe human genome project : will provide help
 Clinical medicine is studying heredity effectsClinical medicine is studying heredity effects

11.  Mutation in genes (e.g., in Huntington’s disease andMutation in genes (e.g., in Huntington’s disease and
cystic fibrosis)cystic fibrosis)
 The transmission of a trait due to a single gene in theThe transmission of a trait due to a single gene in the
human genome is calledhuman genome is called MendelianMendelian transmissiontransmission
 The genes already have been identified for almost allThe genes already have been identified for almost all
Mendelian disordersMendelian disorders
 Mental illnesses are genetically complexMental illnesses are genetically complex
 Important to study the interaction of genes withImportant to study the interaction of genes with
environmental factors in mental illnessenvironmental factors in mental illness

12.  Genes : significant in their aggregateGenes : significant in their aggregate
contribution to riskcontribution to risk
 The Human Genome Project & modernThe Human Genome Project & modern
technologies will help in identification of specifictechnologies will help in identification of specific
genesgenes
This information about genes will be of theThis information about genes will be of the
highest importance because:highest importance because:
 Genes are the blueprints of cells,Genes are the blueprints of cells,
 Provide clues to critical times for interventionProvide clues to critical times for intervention
 Provide insight into environmental risk factorsProvide insight into environmental risk factors

13.  Once a disorder is established as running in families,Once a disorder is established as running in families,
the next step is to determine itsthe next step is to determine its heritabilityheritability, then its, then its
mode of transmissionmode of transmission, and, lastly, its, and, lastly, its locationlocation
through genetic mapping.through genetic mapping.
 Twin studies: one powerful method for estimatingTwin studies: one powerful method for estimating
heritabilityheritability
 Identical twins: share the exact genetic inheritanceIdentical twins: share the exact genetic inheritance
 Fraternal twins: share only 50 percent of their geneticFraternal twins: share only 50 percent of their genetic
inheritanceinheritance
 If a disorder is heritable, identical twins have a higherIf a disorder is heritable, identical twins have a higher
concordanceconcordance

14.  Twin studies do not furnish information aboutTwin studies do not furnish information about
whichwhich oror how manyhow many genes are involved.genes are involved.
 Environmental factors can be significant evenEnvironmental factors can be significant even
with a high level of heritability.with a high level of heritability.
 Environmental factors may even protect againstEnvironmental factors may even protect against
the disorder (if having less risk factors)the disorder (if having less risk factors)

15. Infectious InfluencesInfectious Influences
 Infectious agents can cause mental disordersInfectious agents can cause mental disorders
Examples:Examples:
 ““general paresis”: a late manifestation ofgeneral paresis”: a late manifestation of
syphilissyphilis
 Infectious agent—Infectious agent—Treponema pallidumTreponema pallidum ——
caused “Neurosyphilis”caused “Neurosyphilis”
 HIV-associated dementiaHIV-associated dementia

16.  HIV-associated dementia: 15 percent to 44HIV-associated dementia: 15 percent to 44
percent prevalence.percent prevalence.
 Caused indirectly by infection of immune cellsCaused indirectly by infection of immune cells
known asknown as macrophages.macrophages.
 Other mental disorders caused by infectiousOther mental disorders caused by infectious
agents:agents: herpes simplex encephalitisherpes simplex encephalitis,,
measles encephalomyelitismeasles encephalomyelitis,, rabiesrabies
encephalitisencephalitis, and, and chronic meningitis.chronic meningitis.

17. PANDASPANDAS
 Abrupt onset of obsessive-compulsive disorderAbrupt onset of obsessive-compulsive disorder
symptoms soon after asymptoms soon after a streptococcalstreptococcal
pharyngitis.pharyngitis.
 PANDAS :PANDAS : pediatric autoimmunepediatric autoimmune
neuropsychiatric disorders associatedneuropsychiatric disorders associated withwith
streptococcal infectionstreptococcal infection..
 PANDAS are caused by antibodies against thePANDAS are caused by antibodies against the
strep infection that attack the child’s brain.strep infection that attack the child’s brain.

18. Psychosocial Influences onPsychosocial Influences on
Mental Health and Mental IllnessMental Health and Mental Illness
 Stressful life events, affect (mood and level ofStressful life events, affect (mood and level of
arousal), & personality are prominent psychologicalarousal), & personality are prominent psychological
influences.influences.
 Social influences include parents, socioeconomicSocial influences include parents, socioeconomic
status, racial, cultural, and religious background, andstatus, racial, cultural, and religious background, and
interpersonal relationships.interpersonal relationships.
 Theories of individual behavior and personality :Theories of individual behavior and personality :
psychodynamicpsychodynamic theories,theories, behaviorismbehaviorism, and, and socialsocial
learninglearning theories.theories.

19. Psychodynamic TheoriesPsychodynamic Theories
 Behavior is the product of underlying conflictsBehavior is the product of underlying conflicts
Two major assumptions:Two major assumptions:
 (1) that much of mental life is unconscious, and(1) that much of mental life is unconscious, and
 (2) that past experiences, especially in early(2) that past experiences, especially in early
childhood, shape how a person feels andchildhood, shape how a person feels and
behaves throughout lifebehaves throughout life
 Three parts of personality: the id, the ego, andThree parts of personality: the id, the ego, and
the superego.the superego.

20.  The id : unconscious partThe id : unconscious part
 Ego : rational and reasonable part of personalityEgo : rational and reasonable part of personality
 Ego mediates between the conflicting tendencies ofEgo mediates between the conflicting tendencies of
the id and the superego.the id and the superego.
 Superego : a person’s conscienceSuperego : a person’s conscience
 If the ego is unable to mediate between the id andIf the ego is unable to mediate between the id and
the superego, psychological distress and symptomsthe superego, psychological distress and symptoms
of mental disorders will occur.of mental disorders will occur.
 Conflicts must be understood & resolved.Conflicts must be understood & resolved.

21. Behaviorism and Social LearningBehaviorism and Social Learning
TheoryTheory
 Behaviorism or learning theory : personality isBehaviorism or learning theory : personality is
the sum of an individual’s overt behaviors.the sum of an individual’s overt behaviors.
 Behavior modification: application to treatmentBehavior modification: application to treatment
of mental problemsof mental problems
 LearningLearning : behavior change molded by: behavior change molded by
experience, accomplished through eitherexperience, accomplished through either
classicalclassical oror operantoperant conditioning.conditioning.

22. Classical conditioningClassical conditioning
 Grounded in the research of Ivan PavlovGrounded in the research of Ivan Pavlov
 It explains why some people react to formerlyIt explains why some people react to formerly
neutralneutral stimuli in their environment.stimuli in their environment.
 Example : Pavlov’s experiment with a dogExample : Pavlov’s experiment with a dog
 Dogs learned to salivate merely at the sound ofDogs learned to salivate merely at the sound of
the bell, without any food in sight due tothe bell, without any food in sight due to
conditioning.conditioning.

23. Operant conditioningOperant conditioning
 Described and coined by B. F. SkinnerDescribed and coined by B. F. Skinner
 A voluntary response is strengthened orA voluntary response is strengthened or
attenuated, depending on its association withattenuated, depending on its association with
positive or negative consequences.positive or negative consequences.
 Positive & Negative reinforcementPositive & Negative reinforcement
 Maladaptive behaviors can be unlearnedMaladaptive behaviors can be unlearned
through behavior modification or therapy.through behavior modification or therapy.

24. Social Learning TheorySocial Learning Theory
 The movement beyond behaviorism: by AlbertThe movement beyond behaviorism: by Albert
BanduraBandura
 Greater emphasis on observational learning orGreater emphasis on observational learning or
modelingmodeling
 People’s cognitions—their views, perceptions,People’s cognitions—their views, perceptions,
and expectations toward their environment—and expectations toward their environment—
affect what they learn.affect what they learn.

25. ConclusionConclusion : The Integrative Science: The Integrative Science
of Mental Illness and Healthof Mental Illness and Health
 Findings from different disciplines of theFindings from different disciplines of the
mental health have contributed in themental health have contributed in the
study of mental illness and mental health.study of mental illness and mental health.
 ““Cognitive neuroscience”.Cognitive neuroscience”.