It�s only minutes into our chat and I�m already beginning to get an inkling that Noel Clarke, who has starred in TV shows including Doctor Who and Auf Wiedersehen, Pet doesn�t like me very much.

It's only minutes into our chat and I'm already beginning to get an inkling that Noel Clarke, who has starred in TV shows including Doctor Who and Auf Wiedersehen, Pet doesn't like me very much. Perhaps it's not me per se, rather interviewers as a breed, but as he eyes me suspiciously across the table I'm not exactly feeling a lot of love in the room. We're here - in the bar area of Malmaison in Glasgow - to talk about his new film, Adulthood, a gritty tale of life in the deprived Ladbroke Grove/Latimer Road area of West London, which Clarke has written, directed and also plays the lead role in. The thing is, I have the distinct feeling he thinks I just don't get it: him, the film, its thought-provoking message.

Still, we get off to a good enough start on the small talk. "Can I get you anything, Noel?", asks his publicist. He cocks his head thoughtfully to one side. "Yes, I'll have some Mexican coconut juice from Colombia," he deadpans, before throwing her a grin and adding: "Some still water would be great, thank you." Wearing a beanie hat, baggy jeans, box fresh white trainers and a grey T-shirt with the slogan "Disgruntled Youth" written in jagged letters across it, Clarke looks the epitome of street chic. He gives an elaborate stretch, revealing the Calvin Klein waistband of his pants, before plonking himself down on the sofa.

Adulthood, which marks Clarke's directorial debut, is the sequel to 2006's powerful and disturbing Kidulthood, which he also wrote and acted in. While the first film delved into the lives of today's disenfranchised teenagers, portraying a world where sex is currency, drugs readily available and clobbering someone over the head with a baseball bat is as routine as brushing their teeth, Adulthood aims to offer a more mature viewpoint.

It catches up with Sam Peel (Clarke) upon his release from prison, having served six years for the manslaughter of a rival gang member. The plot follows him over 24 hours as he attempts to make peace with those he has hurt, seeing first-hand the painful chain of events he was the catalyst for all those years ago. As Sam struggles to confront his guilt and adjust to the outside world, he also has to deal with the repercussions of those who now seek revenge for what happened.

I ask about his research methods for the film. With Kidulthood it was reported Clarke, 32, drew partly on his own experiences of growing up in Ladbroke Grove, West London, and also spent a year compiling newspaper cuttings on teenage gangs.

"That's actually an inaccuracy," he says, tetchily. "The newspaper cuttings was me gathering articles, so when people, predictably, said certain things didn't happen I could prove that they did. It wasn't the case that I was looking for things I could put in the film. In early meetings for Kidulthood I had people saying: Well, my kids don't do that' and so I was like . . ." He mimics handing over a scrapbook.

This time around, says Clarke, he has woven in stories of childhood friends with first-hand experience of the scenarios tackled in Adulthood. "There are people I know well who have been to jail and they talked about what it was like for them in there," he says. "So some of the prison stuff is elements of their experiences but also telling the story that the film needed to tell." The prison scenes - in which a warden turns a blind eye, allowing one prisoner to attack another - are among the most harrowing in the film. "We weren't allowed to shoot in any real jails and they told us, predictably, that none of the prison guards are crooked," says Clarke. "But things do happen in prison. Prisoners get attacked by other prisoners. It's awful but it happens. The thing I wanted to show with this film is that prison is not a nice place. I think young people these days aren't scared of it. They don't fear it enough. In a lot of films it looks quite glamorous. People come out and say: I had this and that in my room'. Room? It's a cell."

While Clarke appears to glean credibility from his council estate roots, by the same token he is keen to point out he's actually a clean-living lad. "I've never been in trouble," he says. "My mum used to say to me: We'll get on as long as the police never come knocking at my door' and they never did. I've never done drugs, I don't smoke and I don't really drink." Wasn't it difficult to resist peer pressure growing up? "It was hard in the area I grew up in, most definitely, but something I got from my mum was how to be an individual," he says. "She brought me up on her own. She was strong, and I think I got that from her. I was never a follower. If I wanted to wear different shoes because I couldn't wear the latest trainers, I wore the trainers I could afford and I wasn't scared to do that. I wasn't going to be bullied for it."

There's a guardedness to Clarke and with almost every question he regards me warily. He is brusque, verging on prickly. Not least when I mention the topical nature of the film. Given the burgeoning numbers of knife crime and shootings on the streets, I ask if he feels this will give added weight to the issues he tackles. "That's not the idea," he says, with an edge to his voice. "I didn't write the film to get headlines - I didn't write the first one to get headlines either. I wrote it because it was the story I wanted to tell at the time. I thought it needed to be said and I didn't think people were paying enough attention to what was going on."

After Kidulthood there were those who criticised Clarke, saying the film glamourised violence. Does he expect a similar backlash with Adulthood? "People who have seen it think it's a much more mature film," he says. "The message is clearer in this film. It's about putting weapons down. Even on the poster for Adulthood the baseball bat is on the floor as opposed to over my shoulder. It's about stopping the violence and being brave enough to break that circle. For me, this film is a lot clearer without being preachy. I think people need to know that they have a choice and walk away."

Clarke also visibly bristles whenever we venture into personal territory. So what about his family, I ask? Does he have any brothers or sisters? Clarke eyes me cautiously. "An older half brother," he says, before clarifying quickly: "But I didn't grow up with him, I grew up on my own." So it was just him and his mother? Clarke nods. "Yep," he says. Is he still close to her? "Hmm, yeah." She must be very proud of him? "I guess so. She says she is." Seemingly sensing my frustration, Clarke throws me a grin but doesn't elaborate further.

Having noticed he's wearing a diamond-encrusted band on the third finger of his left hand, I ask about his wife? "Wife?", he says. From the startled look on his face I wonder if I've made a mistake. Boyfriend, I ask? "Boyfriend!", says Clarke, looking perplexed. "What? No, I definitely like the ladies. My wife. I don't want to give her name. We've been married six months. I'm trying to keep her out of the public eye. I don't want to be one of those people that gets so notorious that the media starts following my family."

Fair enough. But by now Clarke is playing coy on almost every question, even refusing to be drawn on that universal favourite of actors: what are you up to next? He alludes to a role in a Philip Ridley film called Heartless, alongside Jim Sturgess and Timothy Spall, but then clams up. "I'm going to appear in something in the next few weeks," he says. "Then there's more stuff, bits and bobs. I can't tell you."

His role as hapless Mickey Smith in Doctor Who helped raise his profile - is there any chance of Clarke making a return to the show? "I dunno, man," he says. "I guess you'll just have to keep watching and see what happens."

Clarke is more forthcoming on the biggest misconceptions about him. "People think I'm this really pleasant, mild mannered, easygoing fellow when I'm actually a quite focused and determined person," he says.

"They see me in Auf Wiedersehen, Pet or Doctor Who and think I'm like that. People get the idea I'm some buffoon that would get stuck to a bin as happened to his character Mickey in an episode of Doctor Who whereas the reality is quite different." Um, quite.

So can he sum up Adulthood in a sentence? "In a sentence?", says Clarke, looking incredulous. Well, two then. "Adulthood is a story of redemption that shows people that there is always a consequence to your actions - and not just for you, but for the people you hurt." Clarke looks me dead in the eye. You can't argue with that.

Adulthood is in cinemas on June 20.