Mechanisms of Pathological Worrying: What Can Studies in the Lab tell us about Anxiety

DisordersGraham C L Davey

University of Sussex, UKhttp://www.papersfromsidcup.com

http://www.psychologytoday.com/blog/why-we-worry

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, Psychological Medicine, 43, 2241-2244) – 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)

Creating and testing potential interventions from models developed in the lab

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 disgust-relevant 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 more likely to contribute to decision-making about perseveration under the following conditions: The less objective knowledge one brings to the judgment task (e.g. problem-

solving 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)

Developing New Interventions:A brief 4-session psychoeducation procedure

Developing New Interventions:A brief 4-session psychoeducation procedure

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10 Reasons why Clinical Psychology needs Experimental Psychopathology1. 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 Psychopathology6. 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 developing psychological models of psychopathology

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