I follow several great blogs, one of them is BPS Research Digest. There I found this blogpost on an interesting study on why people think suicide is morally wrong. A quote:

“The most revelatory finding is that the participants’ ratings for the moral wrongness of suicides was not correlated with their ratings of the harm caused. Rather, their judgment of moral wrongness was correlated with their ratings of how much the victim’s soul was tainted. Consistent with this, the participants’ feelings of disgust predicted their ratings for the moral wrongness of suicide, but their feelings of anger did not.”
Read more here.