Objective: This study uses data from a single subject based on the previously published Randomized Control Trial of Brief Cognitive and Dynamic Therapy (Svartberg, Stiles & Seltzer, 2005). The present study investigates the change of four process variables: Insight, Motivation, Activating affects and Inhibitory affects, both within and across sessions. The study also inquires into whether there are sequential relationships between these four variables. Method: the patient in this study received Short-Term Dynamic Psychotherapy for 40 weeks. The patient met the criteria for a Cluster-C personality disorder. The data consists of process measures from the Achievement of Therapeutic Objectives Scale (ATOS), outcome measures from SCL-90, MCMI-C and IIP, in addition to qualitative observations. Results: The data was analyzed by a two-way Analysis of Variance design, linear regression and a Cross Lagged Correlation design. Variance, trends and the sequential relationships between the process variables were investigated. Results show only small changes in the process variables during the course of therapy. Within a therapy session there were found two small trends of sequential relationships: 1. Affective activation predicted Insight. 2. Inhibition predicted Insight. Conclusion: The overall results showed small changes during treatment. Such finding needs to be interpreted in light of that the patient‘s symptoms and functioning at treatment end and at a 2-year follow-up were unimproved.