Download 10 Reasons why Clinical Psychology needs Experimental

10 Reasons why Clinical Psychology
needs Experimental
Psychopathology
Graham C L Davey
University of Sussex, UK
http://www.papersfromsidcup.com
http://www.psychologytoday.com/blog/why-we-worry
3 Misunderstandings of EP by Clinical
Psychologists/Psychiatrists

The Clinical Psychologist desperately protective of their subject domain

The Journal Reviewer who completely misunderstands the purpose of
Experimental Psychopathology

Experimental Psychopathologists are NOT trying to explain EVERYTHING!
What is Experimental Psychopathology?

The use of experimental models to mimic abnormal processes in healthy individuals
(either animals or humans)

Allows the study of clinical processes under highly controlled conditions

Experiments provide evidence of causal relations between events that are a critical
component of theory building

Experimental Psychopathology regularly borrows from other areas of core psychological
knowledge to understand psychopathology mechanisms

Does most clinical psychology research reflect these principles? – Probably not

Clinical Psychology research is in danger of being highjacked by genetics and neuroscience
because of the poor quality of much empirical research
What makes EP a valid method for studying
Psychopathology?

Vervliet & Raes (2013) – The External Validity of Experimental
Psychopathology

Face Validity

Predictive Validity

Construct Validity

Diagnostic Validity
Face Validity

The degree of phenomenological similarity between the behaviour in the
model and the symptoms of the disorder

The formalistic similarity between the behaviour in the model and the
behaviour in the psychopathology

A relatively weak criterion for external validity
Predictive Validity

The degree to which the performance in the model predicts performance in
the disorder

Can you use the model to predict the performance or outcomes in your
clinical population?
Construct Validity

Requires an elaborated theory of the disorder and of the model, and good
theoretical reasons to assume that the processes described in the model
parallel the clinical process of interest

For example, theories of the psychopathology and theories underlying the
model allude to the same theoretical processes – if so, elaborating the
model can inform knowledge of the psychopathology

Using conditioning theory to elaborate conditioning models of specific
phobias
Diagnostic Validity

Diagnostic validity will demonstrate that the model taps into processes that
are unique to patients or are genuinely representative of patient
populations
Examples of Experimental Psychopathology
Research

Applying conditioning theory to psychopathology (construct validity)

Studying interpretation biases in psychopathology (face validity)

Models of perseverative worrying and rumination (predictive validity;
construct validity; diagnostic validity)

Identifying the active ingredients in interventions and treatments
Applying Conditioning Theory to
Psychopathology

In the 1980s there were many attempts to explain various forms of
psychopathology in terms of conditioning and associative learning

Therefore, study of conditioning principles in lab analogues of
psychopathology should help to elaborate the clinical models

Sensory preconditioning, UCS inflation, Latent Inhibition
Sensory Preconditioning & UCS Inflation
(White & Davey, 1989)

Individual sees a stranger have a heart attack on a bus (sensory
preconditioning)

Later, the individual has a close relative die of a heart attack (inflates
aversiveness of heart attacks)

Individual now becomes fearful of riding on buses

A hypothetical example of how conditioning can explain the acquisition of
fear without trauma being directly associated with the feared stimulus
Sensory Preconditioning & UCS Inflation
(White & Davey, 1989)
•
Test this hypothesis in a formalistically
similar conditioning experiment in the lab
•
Validate the process by identifying
examples of sensory preconditioning and
UCS inflation in the history of individuals
with clinically diagnosed symptoms
(Davey, de Jong & Tallis, 1993)
Davey, de Jong & Tallis (1993)

Case 1. L.L. (male, aged 37 yr) had always
been mildly anxious in social situations, and
this mild anxiety was mostly accompanied
by physical symptoms. The most salient
symptom was intestinal unease. On one
occasion, when L.L. was alone at home and
not anxious at all, similar symptoms of
intestinal unease led to an uncontrollable
attack of diarrhea. From that moment on,
L.L. catastrophically interpreted the
symptoms of intestinal unease that he
regularly experienced in company as a
signal for losing control again. He became
extremely anxious and developed severe
agoraphobic symptoms.

Case 3. M.F. (male, aged 29 yr) worked as a
bank employee. On one occasion the bank
was robbed, and during the robbery M.F.
was threatened with a gun. He had not
been particularly anxious at the time and
returned to work the next day without
complaining of any residual fear symptoms.
However, 10 days after the robbery he was
interviewed by the police, and during this
interview he was told that he was very lucky
to be alive because the bank robber was
considered to be a dangerous man who had
already killed several people. From this
point on M.F. did not return to work and
developed severe PTSD symptoms.
Latent Inhibition & Dental Phobias (Davey,
1989)

Latent Inhibition is the regular prior exposure to a CS without association
with any UCS

Latent inhibition makes it more difficult to associate that CS with a
subsequent aversive UCS

Patients who reported a painful dental experience but did not acquire a
dental phobia were significantly more likely to report a history of dental
treatment favourable to the operation of latent inhibition
Davey (1989) Dental Phobias & Latent
Inhibition
What Psychological Processes contribute to
Interpretation Biases?

Many psychopathologies are associated with negative interpretation biases
(anxiety, depression, etc.)

In the lab, we can explore some of the psychological processes that may
generate interpretation biases

We would then need to search for evidence of predictive validity to show
that these processes are relevant to those creating the biases in individual
disorders

BUT – the knowledge generated by these lab studies is still valuable in that it
can be used to test theories of individual psychopathologies
Experienced Disgust causes a Negative Interpretation
Bias (Davey, Bickerstaffe & MacDonald, 2006)

Disgust is a universal negative emotion

Disgust was becoming implicated in a number of psychopathologies (animal
phobias, contamination fears, OCD washing)

Like anxiety, did disgust cause a negative interpretation bias?

Such knowledge might be useful for elaborating clinical models of disgustrelevant psychopathologies

A benefit of analogue experimental studies is that they suggest that the
processes being studied are not dispositional ones peculiar to certain individuals
Davey, Bickerstaffe & MacDonald (2006)
Barrazonne & Davey (2009)
Construct Validity & Diagnostic Validity

Test the model in healthy individuals – to define the psychological processes
involved (Face Validity)

Test that predictions from the model apply to relevant clinical populations
(Predictive Validity)

Establish that the model taps into processes that are unique to relevant
clinical populations (Diagnostic Validity)
Mood-as-Input and Depressive Rumination
(Hawksley & Davey, 2010)
Depressive Rumination in a Clinical
Population (Chan, Davey & Brewin, 2013)
What’s Unique about Clinical Populations that
makes them Vulnerable to Mood-as-Input Effects?

Meeten & Davey (2011, Clinical Psychology Review)

Mood is likely to contribute to decision-making about perseveration:

The less objective knowledge one brings to the judgment task (e.g. problemsolving confidence)

The higher the concurrent cognitive load (clinical populations tend to adopt
information processing styles that inflict a high cognitive load)

When mood cannot be discounted as a source of relevant information for the task
(clinical populations will usually view the perseverative task as a means to
alleviating or avoiding their negative mood)
What are the Active Ingredients of an
Intervention?

Analogue studies suggest the effectiveness of EMDR treatment of PTSD can
be explained in terms of working memory (van den Hout & Engelhard, 2012)

Recall of memories and eye movements both compete for working memory
resources and this act to blur the memory

Versions of EMDR that don’t utilise eye movements (e.g. use bilaterally
presented tones) therefore shouldn’t work in blurring memories
Van den Hout, Rijkeboer, Engelhard,
Klugkist et al. (2012)
10 Reasons why Clinical Psychology needs
Experimental Psychopathology
1.
Can model psychopathology acquisition processes in healthy participants
2.
Allows the study of psychopathology processes under highly controlled
conditions
3.
Experiments provide evidence of causal relations between events that
are a critical component of theory building
4.
Helps to inject core psychological knowledge into Clinical Psychology
research
5.
Helps to identify the active ingredients in interventions developed
directly from clinical practice
10 Reasons why Clinical Psychology needs
Experimental Psychopathology
6.
Allows the testing of psychopathology models in circumstances where
doing so on clinical populations may be problematic
7.
Can provide Clinical Psychology with a rigorous set of scientific principles
for conducting research
8.
Models developed in analogue studies can provide predictions for future
studies to predict performance in clinical populations
9.
Can help to prevent Clinical Psychology developing incestuous theoretical
practices
10.
Can help prevent Clinical Psychology re-inventing the wheel
Where do we go with Experimental
Psychopathology?

We need to develop an Experimental Psychopathology ‘Manifesto’

We need to be more critical of clinical psychology models that are
developed outside of a genuine experimental framework

We need to ensure that experimental psychopathology is taught as an
explicit component in the training of clinical psychologists

We need more journals that will promote analogue controlled research of
the kind advocated by Experimental Psychopathology
“Must haves” for all Experimental Psychopathologists

Journal of Experimental
Psychopathology

Psychopathology – Second
Edition