Measuring Dysfunctional Interpersonal Beliefs: Validation of the Interpersonal Cognitive Distortions Scale among a German-speaking Sample

Abstract

Backround: Dysfunctional interpersonal beliefs (DIBs) are a key symptom domain in numerous mental disorders. Because DIBs exert a strong influence on social experience and behavior, they play an important role in a mental disorder’s development and chronification. To date, only the Interpersonal Cognitive Distortions Scale (ICDS) captures DIBs independently of specific disorders, populations, or contexts. The aim of the present study was to psychometrically assess and validate a German translation of the ICDS.Methods: The ICDS was administered along with indicators of rejection sensitivity, depressive expectations, interpersonal problems, perceived social support, general psychopathology, psychological distress, well-being, perseverative negative thinking, self-efficacy, and optimism, to both, a nonclinical (N = 114) and a clinical (N = 94) sample.Results: We could only partially replicate the factor structure by EFA and CFA in favor of a three-factor-model. Correlational analyses demonstrated convergent, discriminant, and clinical validity for the “Interpersonal Rejection” subscale, but limited validity for the “Unrealistic Relationship Expectations” and “Interpersonal Misperception” subscales. Internal consistencies were always good to acceptable, except for the “Interpersonal Misperception” subscale in the clinical sample. Mental disorder onset was negatively associated with higher levels of DIBs.Discussion: Our results imply DIBs' relevance to the chronification of mental disorders and their special role in early-onset mental disorders. DIBs should therefore best be assessed with the "Interpersonal Rejection" subscale of the German version of the ICDS, as this subscale revealed the greatest clinical utility. Future studies should improve the others two subscale’s construct validity, e.g., by replacing weak items and adding further classes of DIBs.