The Modified Scale for Suicidal Ideation: factors of suicidality and their relation to clinical and diagnostic variables.

The authors conducted the 1st large-sample factor-analytic study of the Modified Scale for Suicidal Ideation (MSSI; I. W. Miller, W. H. Norman, S. B. Bishop, & M. G. Dow, 1986) on a sample of 330 suicidal young adults. Factor analyses revealed 2 MSSI factors: Suicidal Desire and Ideation (ongoing thoughts or desires about suicide) and Resolved Plans and Preparation (intense thoughts, plans, and courage and capability to commit suicide). The Resolved Plans and Preparation factor was more related to Attempt versus Ideator status than was the Suicidal Desire and Ideation factor. The Suicidal Desire and Ideation factor was more highly related to depressotypic indicators than was the other factor, suggesting that level of depression, although predictive of ideation, may not be as strong a correlate of preparation. Comparison of depression- and anxiety-related diagnostic groups on the MSSI factors revealed little difference, consistent with previous work highlighting the occurrence of suicidality across diagnostic groups. These findings have implications for the structure of suicidality, as well as its clinical assessment.