A question from the National Comorbidity Survey or NCS (Kessler et al., 1999) assessed lifetime ideation, “Have you ever seriously thought about committing suicide?”, and a slightly modified NCS question assessed lifetime attempt, “Have you ever tried to kill yourself or attempt suicide?” We formed three mutually exclusive groups: history of suicide attempt, with or without suicidal ideation (230, 26.2%), no history of attempts but history of suicidal ideation (179, 20.4%), and a non-suicidal group with no history of ideation or attempts (469, 53.4%). Overwhelmingly, suicide attempters reported a history of ideation consistent with ideation being a necessary but not sufficient condition for an attempt (Kessler et al., 1999).
