Language style matching and treatment outcome in anorexia nervosa

OBJECTIVE

Psychotherapy is the treatment of choice for anorexia nervosa (AN) but mechanisms of action are still largely unknown. Growing research suggests that synchrony between patient and therapist contributes to treatment success. Adding to this literature, this study examined the association between language style matching (LSM) among patient and therapist as an indicator of interpersonal (verbal) synchrony and treatment outcome in AN.

METHOD

Audio recordings of mid-treatment therapy sessions (n = 25) in a multi-centre randomized controlled trial on the Maudsley Model of Anorexia Nervosa Treatment for Adults were transcribed and used to calculate LSM for each patient-therapist dyad. These scores were used to predict treatment outcome at 12-month follow-up.

RESULTS

LSM did not predict body mass index (primary outcome) at follow-up. However, higher LSM (M = 0.87, SD = 0.04) was associated with lower eating disorder psychopathology (accounting for 11% of the variance) and higher recovery rates (accounting for 28% of variance) at follow-up.

CONCLUSIONS

These preliminary findings suggest that verbal synchrony between patients with AN and their therapists contributes to favourable treatment outcomes. High levels of LSM may reflect therapeutic empathy, cooperation, or mutual positive perception. Further research should explore the mechanisms of linguistic synchrony with larger samples to allow for stronger conclusions.

Modeling Linguistic (A)Synchrony: A Case Study of Therapist-Client Interaction

Interpersonal synchrony is the alignment of responses between social interactants, and is linked to positive outcomes including cooperative behavior, affiliation, and compassion in different social contexts. Language is noted as a key aspect of interpersonal synchrony, but different strands of existing work on linguistic (a)synchrony tends to be methodologically polarized. We introduce a more complementary approach to model linguistic (a)synchrony that is applicable across different interactional contexts, using psychotherapy talk as a case study. We define linguistic synchrony as similarity between linguistic choices that reflect therapists and clients' socio-psychological stances. Our approach involves (i) computing linguistic variables per session, (ii) k-means cluster analysis to derive a global synchrony measure per dyad, and (iii) qualitative analysis of sample extracts from each dyad. This is demonstrated on sample dyads from psychoanalysis, cognitive-behavioral, and humanistic therapy. The resulting synchrony measures reflect the general philosophy of these therapy types, while further qualitative analyses reveal how (a)synchrony is contextually co-constructed. Our approach provides a systematic and replicable tool for research and self-reflection in psychotherapy and other types of purposive dialogic interaction, on more representative and limited datasets alike.