The Impact of Mental Imagery Instructions on Patients' and Therapists' Positive Affect and Strength-Based Behaviours Within Psychotherapy Sessions: A Randomized Controlled Process Study

Objective

Increased attention has recently been paid to the well-being and flourishing of patients in psychotherapy. This study investigated the occurrence of positive affect (PA) and strength-based behaviours within psychotherapy sessions contrasting positive versus neutral imagery instructions.

Methods

This is a secondary analysis of a randomized controlled trial. Seventy-eight sessions of cognitive behavioural therapy involving 26 patients (69.23% female; M_age = 40.31) treated by 13 therapists were selected. PA and strength-based behaviours of patients and therapists were coded on a minute-by-minute basis with the Resource-Oriented Microprocess Analysis. Each session started with a brief mental imagery instruction. Data were analysed using multilevel modelling.

Results

Mild levels of PA were very common, whereas stronger expressions were occasional, especially at the beginning and end of sessions. Strength-based behaviours were employed in one-fifth of the videos analysed. Therapists in the positive imagery instruction showed more strength-based behaviours in the beginning phase of sessions, p < 0.05. The two imagery instructions significantly differed in the session trajectories of PA, p < 0.05. A quadratic trend with higher initial values and a sharper decline in PA were found in the positive instruction, whereas the neutral instruction showed a flatter trend.

Conclusion

Patients and therapists experience PA and discuss strengths in psychotherapy sessions despite patients' distress. The positive imagery instructions potentially induced a positive focus at baseline for therapists but had a negligible effect on the subsequent session progression.

Trial Registration

ClinicalTrials.gov identifier: NCT03767101 (registered December 6, 2018).