Research shows that dysfunctional sleep-related cognitions play an important role in the development, maintenance and exacerbation of insomnia. This study examines the factorial validity, psychometric properties and both concurrent and predictive validity of the German version of the 16-item DBAS (dysfunctional beliefs and attitudes about sleep) scale. Data was collected in 864 vocational students from the German-speaking part of Switzerland (43% females, M age = 17.9 years). Data collection took place twice within a 10-month interval. The students completed a German translation of the DBAS-16, the Insomnia Severity Index (ISI), the Pittsburgh Sleep Quality Index (PSQI), and provided information about their psychological functioning. Descriptive statistics, factorial validity, internal consistency, gender differences, concurrent, and predictive validity were examined. Confirmatory factor analysis supported the 4-factor structure of the DBAS-16. All factors (consequences, worry/helplessness, expectations, medication) were positively correlated and had acceptable psychometric properties. Females reported higher scores across all DBAS measures. Weak-to-moderate correlations were found between dysfunctional sleep-related beliefs, insomnia and poor sleep quality. Dysfunctional sleep-related beliefs were also associated with decreased psychological functioning, and consistently predicted insomnia and poor psychological functioning at follow-up, even after controlling for socio-demographic background and baseline levels. The present study provides support for the validity and psychometric properties of the German version of the DBAS-16. Most importantly, it corroborates the relevance of cognitive-emotional factors in the onset and maintenance of insomnia and psychological symptoms among young people.
Keywords: Beliefs; Confirmatory factor analysis; Insomnia; Psychological functioning; Sleep-related cognitions; Validity.