Peter Mullan hopes his new film Neds, about youths who drop out of education and turn to violence, will deter young people from such behaviour.
The Trainspotting star and director of The Magdalene Sisters wrote, starred in and directed the film set in Glasgow in the 70s, about John, a bright lad with a violent alcoholic father, played by Peter, who falls in with a gang of "Non-Educated Delinquents".
Peter, who has done volunteer work with gangs, said: "I started off wanting to look at knife culture and then I realised it's not really what the film's about any more. It's more about the journey from childhood to adolescence and hopefully in that journey the film tries to present it as honestly as possible.
"And if it's a dark journey, I guess if there's a message in that, then I hope the message is don't hurt someone in that process."
The film stars 17-year-old Connor McCarron, who has never acted before, but got the part after answering an advert he saw in the local paper.
Speaking at the film's premiere at the BFI London Film Festival, Connor said: "Hopefully real Neds can watch it, real Non-Educated Delinquents can watch it and learn from it. They can say 'What's the point?'."
But the young teen confessed he had enjoyed filming the violent scenes in the dark, gritty drama.
He said: "The reality of fighting is terrible, but the fight scenes, to film, they were pretty good, they were really fun."
The film has already won the Best Film and Best Actor award at the San Sebastian Film Festival.
Peter said: "The awards have really helped the kids. My young actors are chuffed to bits with it and it really builds up their confidence."