[cmsj]

That sounds like a pretty risky and irresponsible sort of study to conduct. It would also likely be extremely complicate to actually get a reliable result, given that people with suicidal ideations are not monolithic. You'd need to do a significant amount of human counselling with each study participant to be able to classify and control all of the variations - at which point you would be verging on professional negligence for not then actually treating them in those counselling sessions.