By MEGHAN COX GURDON

Amy Freeman, a 46-year-old mother of three, stood recently in the young-adult section of her local Barnes & Noble, in Bethesda, Md., feeling thwarted and disheartened.

She had popped into the bookstore to pick up a welcome-home gift for her 13-year-old, who had been away. Hundreds of lurid and dramatic covers stood on the racks before her, and there was, she felt, "nothing, not a thing, that I could imagine giving my daughter. It was all vampires and suicide and self-mutilation, this dark, dark stuff." She left the store empty-handed.

How dark is contemporary fiction for teens? Darker than when you were a child, my dear: So dark that kidnapping and pederasty and incest and brutal beatings are now just part of the run of things in novels directed, broadly speaking, at children from the ages of 12 to 18.

Pathologies that went undescribed in print 40 years ago, that were still only sparingly outlined a generation ago, are now spelled out in stomach-clenching detail. Profanity that would get a song or movie branded with a parental warning is, in young-adult novels, so commonplace that most reviewers do not even remark upon it.

If books show us the world, teen fiction can be like a hall of fun-house mirrors, constantly reflecting back hideously distorted portrayals of what life is. There are of course exceptions, but a careless young reader—or one who seeks out depravity—will find himself surrounded by images not of joy or beauty but of damage, brutality and losses of the most horrendous kinds.

Now, whether you care if adolescents spend their time immersed in ugliness probably depends on your philosophical outlook. Reading about homicide doesn't turn a man into a murderer; reading about cheating on exams won't make a kid break the honor code. But the calculus that many parents make is less crude than that: It has to do with a child's happiness, moral development and tenderness of heart. Entertainment does not merely gratify taste, after all, but creates it.

If you think it matters what is inside a young person's mind, surely it is of consequence what he reads. This is an old dialectic—purity vs. despoliation, virtue vs. smut—but for families with teenagers, it is also everlastingly new. Adolescence is brief; it comes to each of us only once, so whether the debate has raged for eons doesn't, on a personal level, really signify.

As it happens, 40 years ago, no one had to contend with young-adult literature because there was no such thing. There was simply literature, some of it accessible to young readers and some not. As elsewhere in American life, the 1960s changed everything. In 1967, S.E. Hinton published "The Outsiders," a raw and striking novel that dealt directly with class tensions, family dysfunction and violent, disaffected youth. It launched an industry.

Mirroring the tumultuous times, dark topics began surging on to children's bookshelves. A purported diary published anonymously in 1971, "Go Ask Alice," recounts a girl's spiral into drug addiction, rape, prostitution and a fatal overdose. A generation watched Linda Blair playing the lead in the 1975 made-for-TV movie "Sarah T: Portrait of a Teenage Alcoholic" and went straight for Robin S. Wagner's original book. The writer Robert Cormier is generally credited with having introduced utter hopelessness to teen narratives. His 1977 novel, "I Am the Cheese," relates the delirium of a traumatized youth who witnessed his parents' murder, and it does not (to say the least) have a happy ending.

Grim though these novels are, they seem positively tame in comparison with what's on shelves now. In Andrew Smith's 2010 novel, "The Marbury Lens," for example, young Jack is drugged, abducted and nearly raped by a male captor. After escaping, he encounters a curious pair of glasses that transport him into an alternate world of almost unimaginable gore and cruelty. Moments after arriving he finds himself facing a wall of horrors, "covered with impaled heads and other dripping, black-rot body parts: hands, hearts, feet, ears, penises. Where the f— was this?" No happy ending to this one, either.

In Jackie Morse Kessler's gruesome but inventive 2011 take on a girl's struggle with self-injury, "Rage," teenage Missy's secret cutting turns nightmarish after she is the victim of a sadistic sexual prank. "She had sliced her arms to ribbons, but the badness remained, staining her insides like cancer. She had gouged her belly until it was a mess of meat and blood, but she still couldn't breathe." Missy survives, but only after a stint as one of the Four Horsemen of the Apocalypse.