Psychotherapy Process Dynamics and Their Relation to Treatment Success Do Not Differ Across Diagnoses

Area of Science:

• Psychology
• Psychiatry
• Clinical Psychology

Background:

• Psychotherapy research increasingly uses intensive longitudinal monitoring.
• Dynamic patterns of change in patients are crucial for understanding treatment effectiveness.

Purpose of the Study:

• To investigate if diagnostic groups show different dynamic process characteristics during psychotherapy.
• To explore the relationship between within-person process dynamics and clinical improvement.
• To evaluate the utility of a transdiagnostic approach in psychotherapy research.

Main Methods:

• 283 psychiatric inpatients (depression, PTSD, dissociative, personality disorders) completed the Therapy Process Questionnaire daily for ~81 days.
• Calculated eight dynamic process characteristics (variability, autocorrelation, instability, complexity) for each scale.
• Compared diagnostic groups using ANOVAs and examined associations with clinical improvement.

Main Results:

• No significant differences in average process characteristics or their change over time were found across diagnostic groups.
• Idiosyncratic within-person dynamics, not diagnostic categories, appear to dominate psychotherapy processes.
• Clinical improvement correlated with increased mean levels and decreased variability in positive emotions, mindfulness, insight, and motivation, irrespective of diagnosis.

Conclusions:

• Psychotherapy process dynamics are largely transdiagnostic, suggesting individual patterns are more informative than diagnostic labels.
• Measurement-based care should leverage individual process characteristics to guide interventions.
• A transdiagnostic approach focusing on within-person dynamics may enhance treatment personalization and effectiveness.