Can we predict the interpretation of ambiguous symptoms from clinicians’

theories for disorders?

Leontien de Kwaadsteniet & Nancy S. Kim

Research Question

When clinicians have initial hypotheses about disorders/diseases, interpretation of information may get distorted (e.g. Ben Shakar, et al., 1999; Kostolopou, 2009)

Clinicians may arrive at different initial hypotheses, based on the same client information

→ Can we predict clinicians’ initial hypotheses?

This study: Can we predict initial hypotheses from clinicians’ theories for disorders?

More specifically:

Can we predict what diagnoses clinicians rate as most likely, when presented with ambiguous symptoms,

from the causal status of these symptoms in clinicians’ theories for disorders?

This presentation:- Ambiguous symptoms

- Causal status effect

- This study

- Discussion, new study?

Ambiguous symptomsIn clinical practice clients’ problems and symptoms may have

different causes

In DSM-IV different disorders have some symptoms in common

E.g. Depression – Generalized Anxiety Disorder:- sleeping problems- fatigue- difficulty concentrating

E.g. ADHD-Autism- attention problems in ADHD may show in difficulty following social rules – similar to problems in social interaction in Autism (APA, 2000)

Causal status effect

Kim & Ahn (2002): Clinicians weight symptoms differentially which are equally weighted in the DSM-IV, depending on the position of the symptoms in their theories:

Client with symptoms more causally central in theory for disorder → judged more likely to have disorder

More causally central symptoms have more other symptoms depending on them

Theory drawing task

• Different disorders: symptom lists of DSM-IV: criteria and associated symptoms

• Causal relations between symptoms/groups of symptoms • Weak, moderate, strong

Composite drawing anorexia nervosa

Ahn & Kim, 2008

Example

In one clinician’s theory for Anorexia Nervosa (Kim & Ahn, 2002):• “Refuses to maintain weight” causes other symptoms of

Anorexia Nervosa (e.g. excessive exercise, dieting, preoccupied with food)

• “Absence of the period for more than 3 months” does not cause any other symptoms

• Client who “Refuses to maintain weight” rated more likely to have Anorexia Nervosa than client with “Absence of the period for more than 3 months”

• See also Cobos et al., later today? ☺

This study

Can we predict clinicians’ initial hypotheses from their theories for disorders?

Hypothesis:

Clinicians’ interpretations of ambiguous symptoms depend on the causal status of these symptoms in their theories:

Clinicians will interpret ambiguous symptoms as stronger evidence for disorder in which ambiguous symptom is most causally central.

To clarify:• Ambiguous symptom X occurs in disorders A and B• In theory for disorder A symptom X is causally central• In theory for disorder B symptom X is causally peripheral

• Client presents with symptom X• What disorder is most likely: A or B?• Predicted response: Disorder A

A Sx Sy

B Sv Sw Sx

Sz

Method

Participants• 18 experienced clinicians

Procedure

1. Theory drawing:

Participants drew causal relations between symptoms of ADHD, Autism, Depression and General Anxiety Disorder

(symptoms described in criteria & associated symptoms)

(cf. Kim & Ahn, 2002, experiment 1)

Example model GAD

Example model Depression

Questionnaires

2. Questionnaires based on individual models: hypothetical clients presenting with one or two ambiguous symptom(s) Which diagnosis do you think is most likely (0-100), disorder A or B?

• Different causal status in disorders • Rank orders causal centrality calculated from causal models

(cf. Kim & Ahn, 2002)• Control for: criterion or associated • Goal: four hypothetical clients per participant:

– One ADHD – Autism: ADHD most causally central– One ADHD – Autism: Autism most causally central– One Depression – GAD: Depression most causally central– One Depression – GAD: GAD most causally central

Example model GAD

Example model Depression

Problems

It appeared difficult:

- To find ambiguous symptoms that differed (sufficient??) in causal centrality between disorders

- To control for criterium – associated

- To arrive at good formulations

Preliminary results

• 12 Experienced clinicians (Mean experience = 10.2 years; SD = 7.4; 1 man and 11 women)

• On average 2.6 hypothetical clients

• Proportion choices for disorder in which ambiguous symptom is most causally central:– Experienced clinicans: 63% (t(11)=1.3; p=.11 (one-tailed))

Discussion

• Waiting for more data

Problems:• Differences in causal centrality in different disorders often

small (cf. Kim & Ahn, 2002)?• Symptom descriptions deviate from symptoms drawn in

models• Possible confound base rates (ADHD-Autism?)

To do:

• To control for base rates:– Ask participants for base rate ratings? – Use artificial disorders in new study?

Thank you!