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 symptoms In 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 SxSy B SvSwSx 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!