The scales of psychological capacities: Measuring Change in psychic structure

Abstract

Abstract To evaluate long-term psychotherapy with mode-specific measures, the Scales of Psychological Capacities (SPC) have been applied to measure psychic structure and, by repeated measurements, the psychoanalytic construct structural change. This study focuses on stability and sensitivity to change as crucial psychometric qualities of an outcome measure. Stability was studied using the test–retest reliability method with a sample of 20 depressed patients. Sensitivity to change was investigated with a sample of 42 depressive patients by means of a pre–post comparison of the effects of psychoanalytic long-term psychotherapy, an intervention known to bring about structural change. The test–retest study showed no significant change, thus demonstrating stability of the test. The sensitivity to change of the SPC was very satisfactory, yielding an effect size of 1.84 for the SPC total score; this result was also clinically significant (using the Reliable Change Index) when the sample was compared with 60 healthy controls.