A multivariate dynamic systems model for psychotherapy with more than one client.

Area of Science:

• Psychology
• Family Therapy
• Quantitative Psychology

Background:

• Therapeutic alliance dynamics are complex, especially in group settings.
• Existing models struggle to capture multi-person interaction patterns.
• Understanding reciprocal influence in therapy is crucial for process research.

Purpose of the Study:

• To extend dyadic cross-lagged panel models to three-person therapeutic encounters.
• To differentiate between dyadic and group-level interaction processes.
• To investigate the role of physiological regulation (respiratory sinus arrhythmia) in therapeutic interdependence.

Main Methods:

• Utilized dyadic cross-lagged panel models adapted for a three-person group therapy session.
• Analyzed 379 talk turns focusing on fundamental frequency.
• Incorporated respiratory sinus arrhythmia (RSA) as a moderator for each individual.

Main Results:

• Dyadic regression coefficients between pairs (therapist-husband, etc.) were non-significant.
• Eigenvalue/eigenvector decomposition indicated significant interdependence at the whole-group level (therapist-husband-wife).
• Husband's RSA moderated interdependence, with it ceasing during high regulatory effort.

Conclusions:

• Group-level interdependence is a distinct phenomenon from dyadic interdependence in therapy.
• Physiological regulation plays a role in modulating relational dynamics within therapy.
• The extended modeling approach successfully distinguishes between dyadic and group therapeutic processes.