title: Patients' in-session experiences and symptom change: Session-to-session effects on a within- and between-patient level.
abstract: OBJECTIVE
  Knowledge of patients' in-session experiences that lead to symptom change in psychotherapy is limited. This study aims to investigate the within- and between-patient relationships between three in-session processes in psychotherapy (coping skills, therapeutic relationship quality, and emotional involvement) and symptom change on a session-by-session level.
  
  
  METHODS
  Participants (n = 1550) with various disorders, including primarily depression and anxiety, were treated with CBT in a German outpatient clinic. Symptom distress was assessed before each session and patients' in-session experiences were assessed at the end of each session using session reports. Person-mean centering was applied to disaggregate within- and between-patients. Within- and between-patient process scores were tested in multilevel models as predictors of next session symptom change.
  
  
  RESULTS
  On a within-patient level, better session-specific coping skills, better therapeutic alliance, and deeper emotional involvement were followed by next session symptom improvements. In a combined model, only coping skills specifically predicted next session symptom change. Additionally, these coping skills were especially helpful when combined with a better therapeutic relationship quality. On a between-patient level, better therapeutic alliance and more coping skills were associated with lower symptom scores during treatment, while deeper emotional involvement was associated with higher symptom scores. Testing these between-patient effects in a combined model left only coping skills (the more, the greater symptom improvement) and emotional involvement (the deeper, the less symptom improvement) as significant predictors. These two also exhibited a combined effect on symptom change on the between-patient level.
  
  
  CONCLUSIONS
  The results highlight the importance of a thorough disaggregation of within- and between-patient variability in psychotherapy process-outcome research as well as the consideration of several potentially important time-varying covariates. While coping skills showed to be the most central for subsequent symptom change, therapeutic relationship quality only seemed to be a facilitative factor in enhancing these effects, but was not sufficiently helpful on its own.
authors.affiliation: University of Trier, Germany. Electronic address: rubel@uni-trier.de.
authors.forename: Julian A
authors.initials: JA
authors.lastname: Rubel
authors.affiliation: University Hospital of Tuebingen, Department of Psychiatry and Psychotherapy, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Rosenbaum
authors.affiliation: University of Trier, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Lutz
mesh_terms: D000223:Adaptation, Psychological; D000328:Adult; D001007:Anxiety / Q000523:psychology* / Q000628:therapy; D015928:Cognitive Behavioral Therapy; D003863:Depression / Q000523:psychology* / Q000628:therapy; D004644:Emotions; D005260:Female; D006801:Humans; D008297:Male; D010361:Patients / Q000523:psychology*; D011369:Professional-Patient Relations; D016896:Treatment Outcome; D055815:Young Adult
keywords: Coping skills; Emotional involvement; In-session experiences; Person-mean centering; Psychotherapy process-outcome research; Therapeutic alliance; Within-patient associations