The suicide taboo probably extends to the still-living: people tend to shun and distance themselves from the suicidal. This of course makes things worse, pushing people to suicide.
Assuming the taboo could be reversed, we would have friends supporting suicidal friends, even in supporting their desires for suicide. Probably need to decriminalize assisted suicide even by nonprofessional friends. Enemies would of course also support a person's suicide, but assume a suicidal person can easily distinguish between the two, because friends do other things than help you suicide ("Friends help you move..."). (Hopefully the court system can distinguish also.) Amidst all this, the suicidal tendency (and rate) counterintuitively decreases because a person continues to have their support network rather than being shunned.