New research by the Scottish Drugs Forum (SDF) to be released this week reveals just how bleak the picture is for those of the “Trainspotting generation” who got hooked on heroin then failed to clean up their act.

The SDF findings show that 20 years on, Scottish heroin users are so debilitated by long-term addiction that – if they are lucky – they are receiving the same kind of home help services as the elderly. If they’re unlucky, they’re dead: the older Trainspotting generation of addicts makes up nearly half of all Scotland’s drug fatalities.

The SDF research looks at, for the first time, what happened to the Trainspotting generation once they grew up. The term has come to define Scottish drug-users in the 1980s and early 1990s who consumed not just heroin but dabbled in poly drug-use, fell into crime to fund their habit, lived in squalor, were continually in and out of jail, and became victims of HIV and hepatitis-C. In many ways, the Trainspotting generation has come to symbolise the stereotypical Scottish junkie.

Dave Liddell, director of SDF, a non-governmental drugs policy and information agency, said older drug users over 35 are living with the same mental and physical illnesses often seen in the elderly, and so often receiving the same treatment, such as home help assistance with feeding, housework and personal care, and making sure they take medication.

Liddell said older drug addicts had developed “a range of problems just like elderly people do, and like the elderly they don’t want to be in a residential setting, they want to be cared for in the community.

“There are a range of reasons why people can’t care for themselves and that can be health damage like respiratory disease, hepatitis-C, cancer – illnesses that are not part of their active drug use.”

Liddell said there is real concern that the number of older addicts receiving home help assistance will rise if services aren’t improved.

Research also shows there are 15,000 older drug users – around 26% of Scotland’s serious drug-using population – but this relatively small group makes up nearly half of all drug-related deaths.

The General Register Office for Scotland revealed drug-related fatalities increased by 26% in 2007/08 to 574 – the highest number to date. The biggest increase in deaths came among older users.

SDF findings also suggest isolation, depression and loneliness are common among older drug users. Liddell said the vast majority have criminal convictions, have lost most of their family and friends through their addiction and have little or no work history.

He believes a “tailored response” is needed for each individual addict. The solution for Liddell is increased investment so drug workers can spend more time with older users instead of treating them as part of an “assembly line”. He believes the 2500 drug workers in Scotland have become “detached from the individual’s needs”. It is common, he says, for addicts to meet their drug workers just twice a month and often with a different worker each time.

The Trainspotting generation emerged in the mid-1980s when heroin flowed into Edinburgh, Glasgow and Dundee. With the decline of heavy industry and the rise of unemployment in the recession the numbers of addicts soon grew.

Irvine Welsh’s novel Trainspotting was a cult hit after being published in 1993. A film version, directed by Danny Boyle, saw a group of mates play out their drug adventures against a grim 1980s Edinburgh landscape. The combination of slick dialogue and Iggy Pop and Lou Reed soundtrack saw Welsh’s grim vision become a cinematic success.

However, as Ewan McGregor, now a major Hollywood actor, filmed the famous opening scene, being chased along Princes Street by security officers, Stewart – one of the Trainspotting generation – was living the reality.

The 45-year-old’s life parallels the fictive story of the movie’s lead character, Renton. “I was sitting with my cousin and watching him use heroin. I saw him and his pals in these wee flats all using it and then sitting back, looking peaceful and relaxed. I was a mess inside and I thought – I want to be like that, I want some peace.”

Now, when most men his age are thinking about family holidays, company cars and pension plans, Stewart is battling depression while suffering with hep-C, because he shared a needle with an infected user. He used to have a job, a house, a wife and children – but that’s all gone. He hasn’t seen his daughters in 11 years. He’s spent £50,000 on his habit and even the death of a young cousin from an overdose couldn’t make him clean up.

In Trainspotting, Renton travels to England with mates and a huge quantity of heroin which they sell for £16,000. Renton steals the cash and goes AWOL, deciding to “choose life” over drugs. In Stewart’s case, however, he and friends drove to Pollok, in Glasgow to buy heroin in bulk, but his choices led to convictions for drug possession with intent to supply. His criminal past means his ambitions of employment are unlikely to be met. “There are a lot of people who want to give back to society but it’s like society doesn’t want us,” said Stewart.

The best ways to help people off heroin, in Stewart’s opinion, is to put a time limit on how long they are prescribed methadone – many languish on the heroin substitute of years – and for more time with drug workers.

Bill Aitken, justice spokesman for the Scottish Conservatives, said older drug users are part of a “lost generation” with many dying or facing a grim future. “The only way forward is intensive drug therapy and that comes with great cost and the assumption they will co-operate,” he said. “Unfortunately many have shown that they will not do so and we are left with a most difficult problem.”

A Scottish Government spokesman said the 2008 Road to Recovery Drug strategy “makes it clear that we expect there to be a wide range of services in place which should include services for older drug users with more complicated problems”.