Cognitive-attentional syndrome - The psychometric properties of the CAS-1 and multi-measure CAS-based clinical diagnosis.

The Cognitive-attentional Syndrome Questionnaire (CAS-1) is a short self-descriptive measure developed to provide information regarding the severity of cognitive-attentional syndrome, a key construct in metacognitive therapy. The three presented studies explore the psychometric properties of the CAS-1. Study 1 was based on a community sample (N = 1225) and explored the factor structure of the CAS-1, its relations with measures of rumination and metacognitive beliefs, and its demographic structure. Study 2, performed on an internet-based sample (N = 602), explored relations of the CAS-1 with measures of rumination, psychopathology, and quality of life. This study also dealt with the validity of the CAS-1. Study 3 was conducted on participants selected from study 1 (n = 98), based on the results of the CAS-1 and other measures. It explored the predictive validity of the questionnaire's diagnosis through ascertaining clinical diagnoses. All three studies confirm the reliability of the CAS-1. Its validity was confirmed by significant associations with measures of rumination, metacognitive beliefs, psychopathology, and quality of life. Two-factor and four-factor structures of the CAS-1 were confirmed, with the two-factor model better fitting the data. The results obtained show that the CAS-1 has good psychometric properties; its current form is deemed most acceptable for clinical use and we advise use of combined measures of CAS or development of a more expanded measure of CAS for research purposes.