This thesis begins by looking at the issue of trait vulnerability within presuicidal syndrome. The author looks at Suicide Ideation Cognitive Trait Scale (SICTS), and the validity of this test with regards to structure and criterioin orientation. The author also looks at establishing the qualities of stability and discriminability within the continuum. SICTS is able to suggest the existence of suicidal types along a continuum. (figures, references, statistics, tables, tests)