I don't see why some of you think it is vital to have a mentally-healthy participant. The purpose would be to achieve reanimation for the first time. Even if the person did attempt suicide afterward, the experiment would have by then be validated. As soon as reanimation was actually achieved, more participants would most likely follow. The true opponent of this, of course, is the illegality of suicide and the fact many cryogenic preservations are paid for by life insurance companies, who usually refuse suicide cases.