This study aimed to quantify the instability of psychotherapy process variables by using a novel data-analytic approach. The study explored instability of the working alliance over 10 treatment sessions and its relationship with self-esteem.
Data were extracted from a randomized controlled trial, conducted in Switzerland, of a short-term intervention for borderline personality disorder. Sixty clients diagnosed as having borderline personality disorder were randomly assigned to receive either 10 sessions of good psychiatric management-brief version (GPM-BV) or GPM-BV combined with a relational principle called motive-oriented therapeutic relationship. Square successive differences were calculated for client and therapist ratings of alliance instability. Multilevel models were used to test within- and between-person associations of alliance instability with self-esteem.
Although some preliminary analyses showed an association between a more stable alliance and higher self-esteem at the start of psychotherapy, the alliance did not become more stable over time. Alliance instability was not associated with self-esteem at either the within- or between-person level.
This study highlights the advantages, procedures, and challenges of applying square successive differences to psychotherapy research data. The results suggest that the working alliance develops in complex ways and indicate the importance of continuing to use novel methods to capture dynamic psychotherapy processes.