Dermot Fitzpatrick spent 18 years taking heroin and spent most of that time in prison. He describes prison as being "like a drugs supermarket". "You walk around for a while and you'll have four or five people asking you what you're looking for. They're actually selling drugs.
"There are non-users sharing with addicts who are leaving syringes and spikes all over the cells. People are going down to Portlaoise and Shelton Abbey just to get away from it, and their families have major difficulty in visiting them."
When Dermot served his first prison sentence at the end of the 1970s, he told prison doctors he had a drug problem. They gave him a sleeping tablet.
"They weren't used to people coming in the way they come now. There were no detox or maintenance programmes then. Over the years, the prison management have set up some programmes, but I don't think enough is being done.
"People might get a two or three-week maintenance and detoxification crash course in prison even if they've been on physeptone or heroin for years, and that's it.
"The money that's going on prisons is being spent on security - more cages or more barbed wire - and there's nothing geared towards programmes for prisoners. "It costs a lot of money to look after these people medically when they leave prison without having had any treatment. Combination therapy for HIV costs between £12,000 and £16,000 a year. "There's no counselling or no support for people getting out of prison either. People with drug problems are sent out with a black bag full of their possessions and they're lucky if they have £5 in their prison accounts for a taxi home."
Dermot knows from his own experience the ease with which ex-prisoners fall back into the habit of "scoring" heroin and stealing to pay for it. "I was getting out of prison and I wasn't doing anything about my addiction. I was hanging around the same people. Within a couple of weeks, I was strung out again and back involved in crime.
"I had to do something very drastic to get off drugs. The last time I got out of prison, I blanked all my friends. I told them not to knock on my door anymore and that I didn't want to go drinking with them because I wanted to get away from the drugs scene. It was the hardest thing I ever had to do. "It's even harder in prison. As soon as you open your mouth, it's all over prison, and then you've prisoners slagging you, you might get a beating. Why aren't there progressive programmes set up that allow people to take that step forward?"
