The structure of intersession experience in psychotherapy and its relation to the therapeutic alliance.

During the days-long or week-long intervals between their therapy sessions, patients typically recollect, reflect on, practice, and imaginatively elaborate on experiences they had during sessions with their therapists. These "intersession experiences" (IE) have been studied for some time with the Intersession Experience Questionnaire (IEQ) in Germany and the United States. This study aims to compare the factor structure of the English and the German versions of the IEQ and to explore the relation of IE to the therapeutic alliance, as a key process variable usually associated with outcome. Factor analyses on a total of 7,550 IEQ reports from 769 patients in outpatient, day hospital, and inpatient treatment showed almost identical factor structures in both countries and across different therapy settings. Significant associations were found between certain IE factors and therapeutic alliance, varying in strength (0.27≤r(2) ≤0.66) by treatment duration and country. Theoretical, clinical and research implications of the findings are discussed.