I, for one, find the ratings system pretty ludicrous. While I dislike coarse language, and especially detest misuse of the names of God and Christ (indeed, it's partly because of the casual and outright commercial use of the name of the Savior that we block Christian stations from our TV at home), when an otherwise promising movie is given its R rating primarily because of bad language or adult subject matter, we don't consider it necessarily off-limits.
Rather, we are guided by what the film's promoters are promoting. When sex is what they're out to sell, they make no secret of it. Ditto with violent action, politically correct smugness, and promotion of family-hostile lifestyles, not to mention sheer dumbness. There are many ways that movies, songs, books, and television shows can do great social harm. There are plenty of them that I wish had never been created or distributed. But many of the worst are rated well within the so-called "safe" categories, and many fine movies are given "unsafe" ratings for trivial or momentary infractions.
My wife and I also add into the equation the fact that our children are very bright, and we talk to them, and they talk to us. We talk to them about the TV and movies they see, the songs they listen to, the books they read. Often we have found that they and we are better off having seen a show with objectionable parts--and talked about it--than we would have been had we refused to see it at all.
But all those arguments about causality are, ultimately, futile. My children have not been immune to adolescent depression, and it is certainly an issue that needs to be addressed, though I suspect that trying to control, by fiat rather than persuasion, what teenagers listen to is both futile and counterproductive, since the resulting conflict will only deepen the depression and make candid talk about suicidal impulses far less likely. (The principles of Section 121--leading by persuasion, love, and meekness--apply to parental authority, too.)
What really disturbed me about her talk, however, was that for some reason, this sister felt it necessary to go into details about the method the young man in her story used to kill himself, including how he went about making sure that the noise of the gunshot didn't waken his parents.
Now, excuse me, but this was Sacrament Meeting. I had a 6-year-old child there, one who had already had two of her siblings die (of natural causes) in the past three years. I did not need to have her listen to graphic accounts of suicide in church.
Furthermore, that woman had no idea how many of the teens in that audience were suffering from serious depression. If songs, movies, TV shows, and books can influence children to follow bad examples, what about Sacrament Meeting talks?
Did it not occur to her that by giving the details of a suicide, she was providing both an example and an instruction manual to anyone in the congregation who might suffer from suicidal impulses?
Thus our children have grown up participating in American culture while remaining highly critical of it--better armed, I think, in the current culture wars than many children who have had most of contemporary American culture withheld from them. Especially because that which is forbidden offers a far greater attraction than that which is permitted but discussed, criticized, exposed, and rejected.
That's my and my wife's view of the issue, and we have no trouble answering all the temple-recommended interview questions because, contrary to widespread impression, it is not LDS doctrine or even official policy that we must turn over our consciences to the MPAA ratings board. We are expected to use righteous judgment in raising our children, and we do our best. We respect those who use the MPAA ratings as their guide and don't sneak their kids into movies, and we expect them to respect our own equally careful decisions about films and other cultural influences.