Teenage suicide might not instantly seem like the most pre-possessing subject for a movie, but it’s at least worthy of exploration in a teen-flick landscape currently cluttered with vacuous proto-Neighbours romantic comedies and spotty-jerk Porky’s Revenge updates. Originally filmed under the inspired title The Smiling Suicide Club, this home-grown effort is an uneven but clearly heartfelt and genuine entry into the booming Clinically-Insane-People-In-Love genre, and if it never exactly attains the epic resonance of recent precursors such as Angel Baby, On The Edge is never less than an involving and immensely likeable affair.

The plot, it must be said, may not sound like prime multiplex-packing material: a gaggle of inmates in the suicide-watch wing of a psychiatric hospital attend therapy classes, bond/row with one another, and generally rage against their incarceration. Extroverted chatterbox Jonthan Breech – played with remarkable certainty and conviction by possible next-big-thing type Cillian Murphy – is as annoyed with his surroundings as the next inmate: he’s an apparently cheerful and very loud-mouthed nineteen-year-old who would seem to be among the place’s less troubled inhabitants, were it not for the fact that he recently attempted to drive his car off a cliff, and has a history of self-mutilation (’just lettin’ the air outa the tyres’). He does his bit to lighten the atmosphere in the place, while pursuing weirdo American chick Rachel (Tricia Vessey) who also has a penchant for the aul’ carving.

What fun, I hear you yelp, what a fucking bundle of laughs. But don’t worry, this is far from a tortuous depressionfest. Crucially, given the grim context and less-than-cheery worldview which it might seem to necessitate, On The Edge manages to be both funny and (shock!) light-hearted for inordinately lengthy stretches without ever downplaying the depth of its protagonists’ problems, or resorting to idiotic ‘Don’t Worry Be Happy’ platitudes.

All of the acting is first-rate, and if at times the narrative becomes untidy (perpheral character Toby simply isn’t at all interesting), the script’s boundless supply of mordant humour invariably comes to the rescue. Stephen Rea’s masterfully understated performance as the place’s governor – on occasion, his character barely seems to possess

a pulse – is an oasis of calm in a

desert of despair, and Vessey displays beguiling fragility throughout, but it’s mainly Murphy’s moment of triumph, and one senses there might be more to come.

Not destined to smash any worldwide box-office records, then, but On The Edge is far from a waste of two hours’ time.