Psychopathology 751
Ψ diathesis stress models
Ψ uses/problems with diagnostic enterprise
Ψ evolutionary thoughts
theory in psychopathology



Diathesis Complexities—
Include perhaps include cognitive deficits/styles
but harder to differentiate from symptoms of
disorders.
“I favor focusing attention on those at a
somewhat lower level of functioning (soft
neurology and psychophysiology) rather than
social behavior, or even psychometrics, on the
ground that the former kinds of behavior are
closer to the DNA and so have, by and large,
been subject to less influence from complex
social learnings contributing to individual
differences variation and, hence, to increased
statistical overlap.” (Meehl, 1990, p. 3).
theory in psychopathology




Stress—
“an interference or change in conditions
affecting the individual which has an
adverse effect, such as worry or hostility,
especially when prolonged; also external
conditions producing anxiety” Walton,
1985, p.157.
state like (versus trait of diathesis)
desire to create objective, temporally
proximal stress definition.
theory in psychopathology



Difficulties defining Stress—
Difficult but worthy goal to reduce the
reliance on individual differences in stress
definitions (“what makes me stressed out
is…” because these differing stressor may
reflect various diatheses.
e.g., shy people stress in social situations
whereas extroverts enjoy such contact.
theory in psychopathology



Diathesis—Stress Model put forth by
Paul Meehl (1962)
Argued that vulnerability interacts with
stress (i.e., schizogenic mother) to
cause schizophrenia.
Posited that without right kind/amount of
stress, an individual will have a residual,
genetically coded, condition he labeled
schizotaxia which he saw as akin to a
necessary but not sufficient condition for
schizophrenia.
theory in psychopathology

Diathesis—Stress Model

elegant:
– fits data that humans are genetically coded to
be the least biologically determined animals.
We are the animal most open to good and
environmental influence (culture, language)

limitations:
– In the simplified model we are seduced into a
limited view of both vulnerability and stress as
unidimensional but they are not.
– e.g., time of stressor may be very important,
most disorders are polygenic
theory in psychopathology

Diathesis—Stress modified models

additive model
– stress causes x disorder but those with a low level of
diathesis require much more stress…implies that
disorder x will occur with sufficient stress

threshold model
– sufficient diathetic risk required to develop x disorder
– at some threshold of diatheses, the individual will
develop disorder x (without stressors).
theory in psychopathology

Diathesis—Stress complications

diathesis—stress interactions:
– complicate the picture by questioning the
independence of diatheses and stressors.
– diathesis may cause stressors (e.g., traits of
anxiousness and introversion may lead to greater
strain in social support

timing of stressors may be critically linked
– x stressor my be crucial a y developmental window
but not important before/after


multiple genetic pathways may independently
contribute to clinical condition (hard to measure)
genetics probably code for both vulnerability
and protection (stress may work similarly)
psychodiagnosis











Why diagnose? Many clinical reasons…
treatment planning
predict outcomes/responses
protection of consumers (informs client what to
expect)
can be used to communicate empathy
reduce risk of flight from treatment
nomenclature for communication
organize, retrieve info
describe patterns
facilitate theory/research
socio-political functions (who are patients, who
gets to treat whom?)
psychodiagnosis







What’s wrong with the DSM-III (III-R, and IV)?
Valliant:
it is parochial
reductionistic
muddles state and trait
no theory (ignores conflict, adaptation,
development, time course of symptoms)
validity sacrificed for reliability
psychodiagnosis



More problems with the DSM-IV
Co-morbidity threatens specificity of
treatment goal.
not very good reliability under the best of
circumstances
– those kappa estimates are under structured
diagnostic interview conditions but you won’t be
applying the DSM under such circumstances

there is no gold standard (it’s a
consensus/compromise document).
psychodiagnosis


ALTERNATIVE MODELS—
Use taxometrics to help identify discrete disorders
– schizophrenia, schizotypy, unipolar and bipolar
disorders, anti-social PD
– from those probably not; dysthymia, impulse regulation
problems

Dimensional models such as
– Watson and Clark’s
– Eysenck’s Model
– Widiger et al.’s (1987) model with superordinate traits of
social involvement, assertiveness, anxious
A few evolutionary thoughts (de Waal)
a point or two to ponder
the presence of observable behaviors/traits do not
imply adaptive success/fitness.
the position that aberrant behaviors are adaptive has
to account for majority of folks w/out beh.
 rape, murder, etc.
ideas more consistent with the data
we have a wide range of possible behaviors that can
be learned. we are coded to be possible murderers,
rapists, etc.
conservation of form—nature can only use what is
available
if specific traits are not sufficiently maladaptive they
will not be removed from our genotype.
A few more evolutionary thoughts
evolution requires
small isolated gene pool of organisms mating so that a
particular trait can become dominant
 think of the Galapagos islands of Darwin’s finches
 FINCHES!
 Check em out (with pictures!):
 http://www.rit.edu/~rhrsbi/GalapagosPages/DarwinFinch.html
A few more evolutionary thoughts
 "Seeing this gradation and diversity of structure in one small, intimately
related group of birds, one might really fancy that from an original
paucity of birds in this archipelago, one species had been taken and
modified for different ends.”
 Darwin The Voyage of the Beagle, 1909
evolution requires
pressures towards fitness (organisms w/out x trait need
to fail to reproduce or be outstripped in future
procreation)
we are not evolving.
 we do not effectively practice eugenics (Hitler’s efforts
notwithstanding)
 the handicapped/disabled folks procreate
The Concept of a Mental Disorder (Wakefield)
there are no mental illness
labels are used for pathologizing the difficult,
undesirable, etc.: social control.
refutation: yes, there are no ‘diseases’ only what we
decide are natural circumstances that precipitate
death, but there is harmful mental dysfunction.
disorders as whatever professionals treat:
personal attributes that are of therapeutic concern
refutation: not specific enough. what about marital
distress, occupational concerns, etc.
disorder as statistical deviance:
objective/scientific, deviation from the mean.
refutation/problems: what about the other end of
scale?extreme conscientiousness, intelligence,
what qualifies as a dimension? clumsy, short, …
disorder as biological disadvantage
1. harmful dysfunction (science) + values (real harm)
‘dysfunction’ as unfulfilled function-emotions as
information.
(problem here with assumed functions that we don’t
really understand and mental functions may not be as
functionally hardwired but flexible by design.
‘harm’ requires values such as freedom, distress,
symptoms.
fits with Freud (repression) and Behaviorism
(distressing maladaptive behaviors).