Transcript Genes and Behaviour

Explaining Mental Disorder
The study of mental disorder
involves:
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Definition: What do we mean by
mental disorder?
Classification: How do we
distinguish between different
mental disorders?
Explanation: How do we
understand mental disorder?
Treatment: How do we treat mental
disorder?
Different Approaches to Explaining
Mental Disorder
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No completely dominant approach.
Different Approaches to Explaining
Mental Disorder
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All of the approaches we will
explore assume that the proximal
cause of behaviour and experience
is biological.
The approaches emphasize different
distal causes.
Different Approaches to Explaining
Mental Disorder
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Most psychologists today do not
propose linear, one dimensional
causal explanations
Approaches to Explaining Mental
Disorder
Biological / Neuroscience Perspective
Psychodynamic Perspective
Cognitive Perspective
Behavioural Perspective
Sociocultural Perspective
Humanistic / Existential Perspective
Interpersonal Perspective
Biological / Neuroscience
Perspective
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the functioning
of the brain and
other biological
systems
Behaviour Genetics
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Behaviour Genetics
studies the extent to
which mental disorder
is caused by genetics.
The “nature-nurture”
debate explores the
role of genes vs. the
environment.
Behaviour Genetics
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Three different methods are used:
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family studies
twin studies
adoption studies
Family Studies
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Examine family members of an
individual with a mental disorder to
see what percentage of relatives
also have the disorder.
Twin Studies
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Monozygotic twins (MZ) share
exactly the same genotype.
Dizygotic twins (DZ), have 50% of
their genes in common.
Adoption Studies
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Attempt to remove environmental
influence that DZ and MZ twins
share by studying twins that have
been separated at birth.
Adoption Studies
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Adoptions studies still do not control
for all environmental factors
because:
People with the same genes seek
out and elicit the same kinds of
environments.
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Outgoing vs. Shy
Energetic vs. Passive
Genes and Behaviour
Summary
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It is most helpful to think of how
genes and environment interact to
produce disorders.
Interactions, or “that depends”
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What is the influence of X?
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that depends on Y.
The Diathesis-Stress Model
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Individuals inherit tendencies to
express certain traits or behaviours,
which are then expressed or
activated under conditions of stress.
The reciprocal Gene-Environment
Model
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Genes may actually increase the
probability that an individual will
experience a stressful event.
Evaluating the Biological Approach
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Effective treatment does not mean
we understand causation
Side effects of biological treatments
Correlation does not mean
causation
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the disorder could cause the biological
correlate
a third factor might cause both the
disorder and the biological correlate
The Psychodynamic Explanation
of mental disorder
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Psychodynamic Model
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mental mechanisms
emphasis on childhood experiences
emphasis on unconscious motives
Freud and the “Classical”
Psychodynamic model
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Unconscious:
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most mental activity takes place
outside of awareness
the unconscious contains passively and
actively forgotten information
The Structure of the Mind
according to Freud
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Id
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basic primitive biological drives or
instincts
Ego
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develops to help the Id find adaptive
ways to fulfill it’s desires and cope
with reality
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Superego
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internalized moral standards of parents
does not consider what is realistic only
what is abstractly ideal
Competing / Conflicting
Demands on the Ego
Reality
Super Ego
Ego
Mediator
Conscience
Logical / Rational
Illogical / Emotional
Id
The Ego’s Defense Mechanisms
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Ego defense mechanisms involve
distorting or denying internal and
external reality.
Repression
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Repression is the basis of all
defense mechanisms.
Impulses that are unacceptable to
the ego are pushed into the
unconscious
Sublimation
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Sublimation is the most adaptive
defense mechanism
Sublimation is the transformation of
Id impulses into more socially
acceptable forms.
Anxiety
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Anxiety is a signal that the ego’s
controls are at risk of being
overcome by the id or the superego.
The Psychodynamic Explanation
of mental disorder
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Disorder occurs when the ego is not
able to adequately balance the Id,
Superego and reality.
The Psychodynamic Explanation
of mental disorder
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Poor ego defense leads to anxiety
Rigid ego defense leads to
constricted behaviour and
impoverished relationships.
Ego collapse leads to a flooding of
id impulses.
Evaluating the Psychodynamic
Approach
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First well developed approach to
mental disorders that did not
consider mental disorder as a
biological or a moral, religious
problem.
Difficult to subject many of the
ideas to empirical testing.
Gender and cultural bias in original
Freudian ideas
The Cognitive Explanation of
mental disorder
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“Men are disturbed not by things
but by the views they take of them”
Epictetus
Cognitive Appraisal
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Stimulus--->Appraisal--->
Response
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evaluation of stimulus based on
memories, beliefs, and expectations
Cognitive Appraisal
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Appraisals are determined by:
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Competencies (acquired skills)
Perception/Understanding
Expectancies
Values
Plans and Goals
Cognitive Appraisal
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Attribution is an example of an
appraisal
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belief about the cause of an event
 global/specific
 stable/unstable
 internal/external
Information Processing
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Selective Attention
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what information we take in from the
environment (Schizophrenia,
depression, anxiety)
Schema
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how we organize and understand the
information we take in (self schemas)
Evaluating the Cognitive Approach
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Does it explain causes or describe
symptoms? (Why do people have
maladaptive beliefs?)
If an individual could change their
thoughts then they would not have
a problem.
Changing beliefs or views about the
world may not be the best solution
in some situations.
Behavioural Approach
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mental disorder is the result of
“learning” or environmental
experience
The Background of Behaviourism
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Learning
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Pavlov
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the process whereby behaviour
changes in response to the
environment
The conditioned Reflex
Watson
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study only what can be observed
“Little Albert”
The Background of Behaviourism
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Thorndike
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The Law of Effect
Skinner
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Radical Behaviorism
predict and influence behaviour by
focusing on environmental
contingencies
Respondent (Classical)
Conditioning
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UCS -----> UCR
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the unconditioned or unlearned
stimulus causes an unconditioned or
unlearned response
UCS -----> UCR
 CS -----> CR
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after conditioning the conditioned
stimulus causes a conditioned response
Operant Conditioning
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The organism does something or
“operates” on the environment.
The likelihood of a response is
altered by its consequences.
Punishment and Reinforcement
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Reinforcement
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any consequence of a behaviour that
increases the probability of the
behaviour occurring again
Punishment
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any consequence of a behaviour that
decreases the probability of the
behaviour occurring again
Learning Mechanisms
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Extinction
Generalization
Discrimination
Shaping
Behavioural Explanation of Mental
Disorder
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Abnormal behaviour, or mental
disorders are the result of various
environmental experiences (learning
or conditioning)
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eg Dog Phobia
respondent conditioning
 negative reinforcement
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eg Depression
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extinction
Behavioural Explanation of Mental
Disorder
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Less inclined to use Diagnostic
Labels
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symptoms have different functional
roles in different people
Less focused on the past, more
focused on present environmental
factors
Sociocultural Approach
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mental disorder is the result of
social and political factors
Sociocultural Approaches
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Mental disorder is a social label or a
social construction.
Social Construction
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Social Concept
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the boundary between what is and is
not a mental disorder is not “natural”
but “cultural” (think back to mental
disorder defined as a norm violation)
Social Construction
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Social Role
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the “cause” of a mental disorder is the
fact that an individual is fulfilling or
carrying out a social role
this role has a function for the
individual, and/or society as a whole
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Three umpires are sitting around
over a beer, and one says, “There’s
balls and there’s strikes, and I call
‘em the way they are.” Another
says, “There’s balls and there’s
strikes, and I call ‘em the way I see
‘em.” The third says, “There’s balls
and there’s strikes, and they ain’t
nothin’ until I call ‘em.”
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Anderson, 1990 p. 75
Humanistic / Existential Approach
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Natural vs. Human Science
Importance of ‘Understanding’ and
entering into subjective world of client
Emphasis on uniqueness of each person
rather than general patterns
Agency
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Contrast with determinism
Authenticity, Freedom, and Responsibility
Humanistic Approach
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‘Acorn’ Theory
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Potential and Uniqueness
Fulfill possibilities
Self actualization