Nicola has the sunken face of a long-term junkie. She looks about 50 but is probably much younger. She is painfully skinny in tight jeans and her shoulder blades poke through her white cardigan. She wears thongs even though it’s winter.

Nicola has just taken the stand in the Drug Court of NSW, where for the past five years Roger Dive has been the senior judge. He is in his fifties, with grey hair and a kind face. He reads Nicola’s case notes.

“What’s gone wrong?” is his first question.

“I missed a urine test,” Nicola replies. “I had an abscess on my tooth and I went home and I ended up falling asleep.”

Judge Dive pulls her up. “You’re using speed and ice all the time and you’re not telling us.”

There’s a long silence. “Yeah, that was last week. I was having a bad week,” Nicola explains. “I’ll speak to my counsellor next week. She says sometimes a relapse can make you stronger to carry on.”

“No, no, no, it’s a complete picture of disaster here,” Judge Dive says. He orders her to serve 21 days in prison after which she’ll resume the Drug Court program.

Nicola looks shocked. “Can I just have a chance?” she begs. “Please, Your Honour. I’ve learned my lesson well.”

Judge Dive is immovable so Nicola quietly removes her jewellery and gives it to a young man sitting in the public gallery. Two policemen then lead her downstairs to a holding cell to await transfer to Silverwater Prison.

The Drug Court of NSW, which marks its tenth anniversary this year, was established as an experiment to tackle the causes of crime rather than just mete out punishment. It is a kind of purgatory between two hells: jail and the offender’s regular life of drug addiction. Addicts, like Nicola, who appear in a regular court and plead guilty to non-violent offences, are eligible to attend Drug Court instead of going to jail. They undertake rehabilitation and treatment. But if the offenders flout strict conditions, including drug testing and counselling, they have to serve their original prison sentence.

“G’day Jason, how are you today?” Judge Dive asks another of the clients, as those to appear are called. Jason starts a long rant about how he almost had an altercation with a car driver.

“I was walking across a crossing and this motorist didn’t stop,” Jason says, twisting a blue-striped beanie in his hands. “I didn’t beat him up or nothing. I do boxing three days a week at the gym, Your Honour. But he says his mates are gonna get me, gonna bash me or something. I don’t have no bad feelings or nothing. I just want an apology.”

“OK, Jason, I’m going to stop you there, OK?” Judge Dive interrupts. “It looks like you handled a very difficult situation well, you walked away. Good work.”

Although the court looks deceptively normal – Judge Dive wears black robes and there’s a bench, a bar table, a dock and a public gallery – it is far less formal than a routine hearing. One thing in particular distinguishes this courtroom from any other: offenders who are doing well are applauded. In Jason’s case, unlike Nicola’s, the drug tests are clean and so at Judge Dive’s direction, everyone in the room claps warmly. Jason is beaming as he leaves.

“I was a little doubtful, when I started, about the applause being necessary,” Judge Dive confides later over lunch in his chambers. “But you only have to be here for a day when you see how much they glow with pleasure when they receive it. I think they’ve probably never had any positive reinforcement in their lives before.” He recalls one young program participant who was crestfallen when he saw that the public gallery was almost empty on the first day he qualified for applause. “He asked me if he could wait until there were a few more people,” Judge Dive says. “When we had a reasonably full court a while later, I said to him, ‘Are there enough people now, Dylan?’ and he said there were, so we gave him the round of applause and he was very happy.”

According to the Drug Court’s own assessment, 45% of the cases that appear before the court are deemed “successful”, meaning the participant doesn’t return to prison at the end of the process. The NSW Bureau of Crime Statistics monitors the court’s effectiveness and has found that offenders who complete the Drug Court program are 17% less likely to be reconvicted than those who go through the usual court system. The program is also more cost-effective than prison. A decade after its creation, the Drug Court has bipartisan support in NSW and similar courts exist in other states.

Judge Dive obviously takes pride in the success stories. He keeps a thick ring-binder on his bookshelf, its plastic sleeves stuffed with thank-you letters. As for the cases that don’t work out, he says he can emotionally distance himself. “Your disappointment is more for them,” he says. “I try to reassure them that this is your recovery, we’ll get over it if it goes bad because we’ll just transfer our care and commitment to the next person that takes your place.”

Offenders take the stand one by one during the day and Judge Dive chats to them about the minutiae of their lives: busted knees, vet bills, job troubles, parental woes. Adele stands before the court with a toddler clinging to her legs and a tiny infant in her arms; she looks all of 20, but she’s staying off drugs and wins applause. Kerry is middle-aged and has been clean for a while; she’s about to finish her Drug Court course but she’s nervous about whether she can make it on her own. Jackson’s arms are covered in tattoos and he has been back in prison for violating Drug Court rules; he’s getting one final chance and will move into a rehabilitation centre full-time. Helen looks like a tuckshop mum; it’s hard to imagine that she was found guilty of such a serious drug offence that she’d be in prison if not for this court.

One of Judge Dive’s final cases for the day is Roy, an Asian man in his early thirties charged two years ago with shoplifting and heroin possession. Today, he has a new job and a new wife and he is graduating from Drug Court. He’ll be on a good behaviour bond for six months. Judge Dive walks out from behind the bench to shake Roy’s hand and give him a certificate of achievement. “Well done, good for you,” the judge says and everyone applauds heartily. “Drop in to see us sometime.” Roy bounces out of the court with a broad smile as Judge Dive returns to the bench and calls the next case.