Treatment credibility as a mechanism of change in cognitive behavioral therapy: Effects on depression and anxiety.

OBJECTIVE: This study aimed to provide evidence for treatment credibility (TC) as a potential mechanism of change in cognitive behavioral therapy (CBT). Therefore, it focused on within-person effects that are free of the influence of stable characteristics and thus allow to exclude certain alternative explanations for the association under study. METHOD: The sample included 1,423 patients receiving outpatient CBT, who presented a wide variety of psychiatric diagnoses (mostly affective and anxiety disorders). TC, depression, and anxiety were measured every fifth session from Session 5 to 25 using the Credibility Expectancy Questionnaire (CEQ), the Patient Health Questionnaire-9 (PHQ-9), and the General Anxiety Disorder-7 (GAD-7), respectively. Symptom severity was assessed every session using the Hopkins Symptom Checklist-11. Within- and between-person effects of TC, depression, and anxiety were analyzed using the latent curve model with structured residuals (LCM-SRs). In exploratory analyses, within-person effects of TC on next-session symptom severity were assessed using a modification of the LCM-SR. RESULTS: LCM-SRs exhibited excellent fit in main analyses. There were significant negative correlations of both intercepts and slopes (between-person level) of CEQ and PHQ-9 as well GAD-7. No significant cross-lagged effects (within-person level) were found over the five-session interval. However, session-wise analyses revealed significant cross-lagged effects of CEQ on Hopkins Symptom Checklist-11. CONCLUSIONS: This study is the first to find significant within-person effects of TC in session-wise analyses. This lends preliminary support to the notion of TC as a mechanism of change. The lack of significant findings at the five-session interval is discussed considering the specific design used in this study. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Development and validation of the Inventory of Depression and Anxiety Symptoms-II-German version.

The expanded version of the Inventory of Depression and Anxiety Symptoms (IDAS-II) is a 99-item self-report measure containing 18 nonoverlapping dimensional scales assessing symptoms of depression, anxiety, and mania. The aim of this study was to develop and validate a German adaptation of the IDAS-II. Participants from a community sample (N = 1,054) completed the IDAS-II (German version). In addition, part of the sample (N = 550) completed a series of additional measures of depression (Patient Health Questionnaire-9, WHO-Five Well-Being Index, Symptom Checklist-90 Revised-Short Version) and anxiety disorders (Generalized Anxiety Disorder Scale-7, Fear of Negative Evaluation Scale-5, Dimensional Obsessive-Compulsive Scale, The International Trauma Questionnaire). We conducted item-level confirmatory factor analyses (CFA) separately for the 15 nonsaturated IDAS-II scales, which confirmed unidimensionality. McDonald's ω indicated good internal consistency (ω > .8) of all symptom scales except Euphoria (ω = .751) and Ordering (ω = .728). A CFA of the IDAS-II scales, based on exploratory results by Watson et al. (2012), confirmed a three-factor model of "Distress," "Obsessions/Fear," and "Positive Mood." Correlational analyses with additional symptom measures supported the convergent and discriminant validity of the IDAS-II scales. The IDAS-II (German version) allows for a reliable assessment of the severity of depression, anxiety, and bipolar symptoms and is one of the first clinical measures for German-speaking samples that is consistent with the Hierarchical Taxonomy of Psychopathology (HiTOP). (PsycInfo Database Record (c) 2022 APA, all rights reserved).