Psychotherapist's Nonverbal Coordination Scale: Introducing a New Measurement Tool for Child Psychotherapy.

Objective: Current study aims to develop an observer-based rating system, Psychotherapists' Nonverbal Coordination Scale (PNC), to evaluate psychotherapists' ability to coordinate their nonverbal expression and body movement with those of the patient in child psychotherapy.

Methods: PNC was implemented in a clinical trial of Mentalization Based Treatment for Children (MBT-C) involving 101 children and their 16 therapists. 269 videotaped sessions from three different time points in treatment were coded with PNC by trained coders. Sessions were also coded for affect regulation and adaptive play qualities. Child-reported therapeutic alliance and parent-reported child problem measures were collected after the sessions. Multilevel Modeling was utilized to evaluate PNC's convergent and criterion validity based on its association with these process and outcome variables.

Results: Excellent inter-rater reliability was achieved among coders. PNC's convergent validity was supported through its positive correlation with the Attention Control Interventions of the MBT-C Adherence Scale. PNC total score was also found to predict better affect regulation and increased adaptive play within sessions as well as stronger therapeutic alliance and a steeper decline in symptoms.

Conclusion: This study provides initial support for the use of PNC as a reliable and valid tool to evaluate therapist's skill level in nonverbal coordination.