The number of 18 to 24-year-olds in England entering treatment for addiction to heroin has plummeted 79% in 10 years, as the stigma surrounding the drug and changing tastes in intoxication have made it increasingly unfashionable.

In the year to March, 2,367 people from that age group presented with heroin and opiate addiction at the approximately 900 drug treatment services in England, compared with 11,351 10 years earlier, according to statistics from the National Drug Treatment Monitoring System (NDTMS).

They constituted a tiny fraction of the 149,807 opiate addicts who came for help to kick their habit throughout the year, a number that is itself 12% down on a peak of 170,032 who came for treatment in 2009-10. The median age of those users was 39, the statistics showed.

Michael Linnell, the coordinator of UK DrugWatch, a network of drug treatment professionals, said many of the heroin users currently accessing treatment would have become addicted during a boom in the drug’s popularity in the late 1980s. Young addicts were “as rare as hen’s teeth”, he said.

“For the Thatcher generation who didn’t see a future and there were no jobs or employment and the rest of it, it was an alternative lifestyle in that you were really, really busy being a heroin user: getting up, scoring, nicking stuff to get the money to score and the rest of it,” Linnell said.

“There was a whole series of factors until you got to that point where people from those communities – the poorest communities – where you were likely to get heroin users, could see the visible stigma of the scarecrow effect, as some people called it.

“They didn’t want to aspire to be a heroin user because a heroin user just had negative connotations, rather than someone who was rebelling against something.”

Overall, 288,843 adults aged 18 to 99 came into contact with structured treatment for drug addiction during 2015-16, 52% of whom were addicted to heroin or some other opiate. Among opiate addicts, 41% were also addicted to crack cocaine, with the next highest adjunctive drugs being alcohol (21%) and cannabis (19%).

About half of those presenting to treatment – 144,908 – had problems with alcohol, a fall of 4% compared with the previous year. Among those, 85,035 were treated for alcohol treatment only and 59,873 for alcohol problems alongside other substances.

The most problematic drug among the 13,231 under-25s who came into contact with drug treatment services in the past year was cannabis, which was cited as a problem by 54%, followed by alcohol (44%) and cocaine (24%).

The numbers from this age group accessing treatment had fallen 37% in 10 years, which the Public Health England report accompanying the statistics said reflected shifts in the patterns of drinking and drug use over that time, with far fewer young people experimenting with drugs than in the past.

Karen Tyrell, the spokeswoman for the drug treatment charity Addaction, said the decline in problem drug use among young people reflected what drugs workers see on a daily basis, and credited evidence-based education, prevention and early intervention programmes for the change.

The shift, though, was precarious, Tyrell said, warning that yearly spending cuts to treatment services risked reversing the gains.

She added: “Of course, what this also means is that we have an ageing population of heroin users, many of whom have been using since the 80s or 90s, and who are now dealing with poor physical health and increasing vulnerability. In an environment of ever rising drug-related deaths, it’s imperative we don’t lose sight of their needs.”