Scale for Suicide Ideation: psychometric properties of a self-report version.

A self-report version of the Scale for Suicide Ideation (SSI) was administered to 50 inpatients diagnosed with mixed DSM-III psychiatric disorders and 55 outpatients with affective disorders. The self-report SSI was written for both paper-and-pencil and computer administration. The correlations between the self-reported and clinically rated versions for both inpatients and outpatients were greater than .90, which suggests strong concurrent validity. The Cronbach coefficient alphas for the paper-and-pencil and computer versions were also in the .90s and indicated high internal consistency. Furthermore, the mean SSI scores of the computer version for both the inpatients and outpatients were higher than the mean SSI scores of the clinical ratings; the patients described more severe suicide ideation than clinicians reported.