Psychometric properties of the German version of the suicide cognitions scale in two clinical samples

The present study aimed at evaluating the psychometric properties of German Suicide Cognitions Scale (SCS-18/SCS-9) in two clinical samples. Validity and reliability were established in an outpatient- (n = 277) and in an inpatient sample (n = 75). Statistical analyses included confirmatory factor analyses, correlation analyses, between-group comparison by history of lifetime suicide attempts, and regression analyses. The three-factor model showed good model fit for the long version of the SCS (SCS-18). For the short version of the SCS (SCS-9), a bifactor model yielded the best fit. Overall, the total scale of the SCS-18 and the SCS-9 and the subscales of the SCS-18 showed satisfactory internal consistency, as well as good convergent validity. The SCS-18 subscales and the SCS-9 demonstrated clinical utility by differentiating between participants with prior and without prior suicide attempts. The SCS (subscale unsolvability and SCS-9 score) predicted current suicide ideation as well as suicide ideation 7-10 days later - even after controlling for established risk-factors (e.g., depression, hopelessness, interpersonal variables). Results suggest that the SCS-18 and the SCS-9 are reliable and valid measures to assess suicidal cognitions that can be used in clinical as well as in research settings.