Heart Rate Variability and Attachment as Client Predictors of Psychotherapy Outcomes

This study examines the role of client-level psychophysiological and relational factors in predicting psychotherapy outcomes in naturalistic clinical settings. Specifically, it investigates whether pre-therapy attachment orientation (anxiety and avoidance), heart rate variability (HRV), and working alliance contribute to changes in psychological distress, symptom severity, and subjective well-being.

A longitudinal, single-arm design was implemented with adult clients receiving outpatient psychotherapy (up to 16 sessions). Resting HRV was assessed via electrocardiogram and indexed using RMSSD and respiratory sinus arrhythmia (RSA). Attachment was measured using the Experiences in Close Relationships questionnaire, and working alliance was assessed at multiple time points. Outcomes included the OQ-45, SCL-90, and Satisfaction with Life Scale.

Hierarchical regression models were used to test the incremental and interactive contributions of attachment, alliance, and HRV. The study aims to clarify the relative and combined influence of embodied regulatory capacity and relational factors on therapeutic change, contributing to process–outcome research and informing clinically relevant models of psychotherapy effectiveness.