"Daddy wanted to see you yesterday but mummy wouldn't let him," says Corey Kennedy, holding his young son Liam behind the driver's seat of a car. "[She] makes up excuses all the time."

Mummy has good reasons, though. Corey is an ice addict – and seems high as he cradles his son. He's twitching, crying, swearing and yelling as his exasperated family sit watching this awful spectacle from the porch of their Mount Druitt home.

Shantelle, Corey's girlfriend and mother of his child, left him and moved into the Kennedy family's home.

"I don't care any more," she says. "I tried to help him get away from the stuff but everywhere he goes he gets it. I'm just going to have to call it quits and just let him go his own way."

This is the very real impact of ice – or crystal meth – on people, families and places, as told with seemingly no sugar-coating by SBS documentary Struggle Street. The concluding episodes, aired nationally on Wednesday night, showed a mother and father at their wits' end with their son's addiction and resultant behaviour.

"I've had enough," yells father Ashley, sitting on the couch a few inches from wife Peta and white hot with rage.

"Enough. It's coming to a f---ing point now, it's f---ing over. Anyone else comes here on the f---ing drugs, well I'm gonna go off.

"Whether it be me son, whether it be me daughter, whether it be me grandkids, whether it be me father, my mother, anybody. I don't give a f---, I've had enough."

The rawness of the emotion makes for difficult viewing. Struggle Street has been accused by some, including Peta Kennedy herself, of selective editing and exploiting its participants. But to an extent, the camera does not lie. In one of the documentary's most harrowing moments it captures Ashley, furious, marching over to Corey's car and appearing to take a swing at his son's face.

"Go write yourself off you f---wit," he yells as Corey speeds off. "Go and kill yourself you f---ing dog."

Ice sometimes seems like somebody else's problem; the scourge of small towns, ravaging the regions of Australia. The stats and the stories tell of the devastation it has wreaked in regional Victoria, among other areas.

Struggle Street shows – for those who need reminding – that ice is everywhere. And though this documentary focused on a very disadvantaged community, it is a drug that is by no means exclusive to the poor and marginalised. As Fairfax Media's Eamonn Duff has written, ice is everyone's problem.

It is not just ice, plainly, that seeps into communities such as these. Bob, a 47-year-old heroin addict (and more recently an ice user), exemplifies the pathetic waste brought about by hard drugs. Thirty years of junk have contorted his face, which appears squashed in and roughed up. He cowers silently on the bed when housing department officials come to inspect his house, pretending nobody is home.

In another scene, Bob's girlfriend, 21-year-old Billie Jo Wilkie, is seen smoking pot in the final weeks of her pregnancy, and begging her mother for a cigarette while in labour.

This is all happening 43 kilometres from Macquarie Street, where attention is sure to turn for some sort of solution to the mess highlighted by this program. Support services in the area are under pressure, following cuts in federal funding.

Blacktown mayor Stephen Bali, one of Struggle Street's loudest critics, told Fairfax Media after the first episode: "If you watch that show and you felt these people need to be helped … well, the very organisations that help these people … these very social supports have just been taken away from them."

Corey gets no help – at least, not that we can see in this documentary. He quite literally drives off into the sunset, thrown out by his family, rejected by his girlfriend, stripped of his son. It is made quite clear that he has had enough chances. From now on, he will have to choose to help himself.

For Corey's family, the dogs bark but the caravan moves on. At the series' end, they are seen gathered around a television screen, watching a home video put together by resilient matriarch Peta. It is a gift to husband Ashley, who has been diagnosed with dementia and Alzheimer's, on top of his existing heart problems.

The documentary series – with its messages of love and support from his children – is both a tribute and a preparation for the worst. But there is one notable absence.

"You do have a son named Corey who went off the rails," says Peta. "But he will get better."

So far, though, he hasn't.

Fairfax Media spoke to the Kennedy family on Thursday. It has been five months since Struggle Street finished filming in Mount Druitt, but little has changed. Shantelle and Liam are now living with Shantelle's mother, Ashley says, and the pair are doing well.

The Kennedy family are still struggling – "battling through day by day", in their words – and fielding countless interviews as the public feasts on their formerly private lives.

And Corey, now 25, is ever the same. Ashley says his son is still using, and tried to visit the family a few nights ago at 2am, high on ice.

Ashley says his son will have to go to jail or rehab before he's welcome back at the family home. He's counting on the documentary to do what everyone else in Corey's circle has so far been unable to achieve – a successful intervention.

"I hope somebody's going to take it on board and help him out, otherwise I'm going to find him dead," Ashley says.