At a recent London conference on teenage fiction the suggestion was made, by author Nicola Morgan, that the time has perhaps come when this particular area of writing should be treated as a branch of adult, rather than children's, literature.
As the first teenage novels of 2004 begin to arrive, it is a point of view which attains increasing credibility, given that in many cases they embody, both in theme and style, content which until very recently would have been seen as the concern of writing for an older age group.
Such developments are the inevitable consequence of changes in societal attitudes, whereby the boundaries between childhood, adolescence and adulthood are less and less sharply defined. In literary terms, the real test of the success, or otherwise, of the "crossover" effect will be the quality of the writing and the extent to which it is perceived by adult readers as offering the same level of intellectual, emotional and aesthetic reward as that provided by the best of "adult" writing.
Judged by these criteria, a novel such as Chris Lynch's Freewill (Bloomsbury, £5.99) admirably passes the test and indeed is so stylistically sophisticated that it might be fully appreciated only by those with considerable reading expertise. Narrated, very unusually, in the second person and hauntingly employing snatches of the Sinatra song Summer Wind as its leitmotif, the novel focuses on Will, a teenager recovering from the deaths of his father and stepmother. The lack of precise information about the circumstances of these deaths is reflected in numerous other uncertainties of detail but what is never in question is the boy's anguish as he works his way through the depression of "the days . . . those lonely days . . . go on, and on". The novel's title and its subsequent division into three sections - "Faith", "Hope" and "Charity" - provide an appropriate framework for an extremely touching depiction of adolescent bewilderment and an eventual resolution.
Death and its surrounding mysteries lie also at the heart of Kevin Brooks's Kissing the Rain (The Chicken House, £12.99). Did its 15-year-old hero, the overweight and outcast Moo Nelson, really witness a murder, as he is initially convinced he did, and why are there so many conflicting interpretations of it, its origins and consequences? Here is a work of fiction which tellingly focuses on the nature of truth and lying, their coalescence and their divergence. Trapped, like Lynch's Will, in a loneliness from which all certainties have long vanished, Moo has his introspection brilliantly conveyed in the jerky rhythms of Brooks's prose, assisted by typographical experimentation which becomes an integral element of the plot's structure.
Matt Whyman's Boy Kills Man (Hodder, £10.99) is, in many respects, the most "adult" book reviewed here - notwithstanding a hero, Sonny, who is all of 12 years of age. The setting is the Colombian city of Medellin, an environment where gunshots are "as common as car horns" and where young killers chillingly pursue their horrendous trade in a heady, drug-ridden atmosphere of civic and governmental corruption. If, as the novel's opening sentence informs us, "nothing is more unsettling in this world than a kid with a gun", then it must be conceded that Whyman presents, with a vision that at times is almost frightening in its focus, a narrative which demonstrates precisely how "unsettling" such a spectacle is. This is a tough, uncompromising - and very impressive - piece of writing.
"Eighteen is nearly grown up, isn't it?" reflects Flora Baxter, the narrator, at one point in Adele Geras's Other Echoes (David Fickling, £9. 99). Convalescing in her English boarding school, she decides to write, in the form of a memoir, an account of her childhood as a member of the British expatriate community in the north Borneo of the 1950s and, in the process, to explore the nature of memory and those "other echoes" which continue to haunt her. The period details of the privileged and protected setting are very attractively sketched but what emerges even more strikingly is a child's gradual (and occasionally disconcerting) penetration of an adult world of secrets and subterfuge.
The dying Australian town which serves as background for Sonya Hartnett's Stripes of the Sidestep Wolf (Walker, £5.99) may be neither "privileged" nor "protected" but it certainly directs the destinies of those who, with varying degrees of acquiescence, live there. The spotlight is principally on Satchel O'Rye, soon to enter his 20s but still at home with his parents, whose life is to change significantly with his sighting of the animal known as the Tasmanian tiger, previously thought to be extinct. Hartnett's novel deals with the parallel themes of human and animal survival in a manner which more than fulfils the promise of its epigraph, Blake's "everything possible to be believed is an image of truth".
Only the very best of our new "crossover" teenage fiction will successfully translate such possibilities into such truths.