Research led by the National Drug Evidence Centre at the University of Manchester has found that drug misuse seems to have passed its peak in some previous problem areas.
Mr Tim Millar and colleagues investigated the reality of the situation in perceived drug trouble-spots by estimating trends in the ?incidence1? of heroin use (i.e. changes in the number of people starting to use heroin). These indicated geographical differences in the progress of heroin ?epidemics?, and suggested that problem drug use (PDU) is declining in some areas considered hot spots in the 1980s.
The study, undertaken with the Centre for Drug Misuse Research at the University of Glasgow and funded by the Home Office Drugs & Alcohol Research Unit, looked at data on almost 15 000 problem drug users using heroin who sought treatment in Greater Manchester between 1986 and 2000.
It used a new approach which takes account of the time-lag between people starting to use heroin and their coming forward to seek help, and focused on the City of Manchester, Stockport and Wigan. These areas exhibited the clearest patterns in the age-specific prevalence2 estimates produced using the traditional approach as part of the same study.
Mr Millar said: “Problem drug-use prevalence estimates for Wigan progressively declined with age, suggesting a younger PDU population than the other areas. This meant young people must have recently been recruited into the PDU population at a faster rate than previously, suggesting that problem drug use incidence would have recently increased in the area.
“The incidence-rate estimates we produced using the new method supported this, increasing for heroin use during the 1990s.
“By contrast, prevalence estimates for the City of Manchester indicated an older problem drug use population (mainly 25?34 years), prompting us to think that incidence might be in decline – with the rate at which young people are recruited into the PDU population waning and those recruited during an earlier epidemic phase ageing. Our incidence-rate estimates corroborated this, indicating a decrease during the 1990s.
“In Stockport, the prevalence estimates showed less difference between age-groups, suggesting incidence had remained stable, and this was backed-up by our incidence-rate estimates.
“Our theory that the areas would exhibit different patterns of recent incidence trends – with some places having ?passed their peak? whilst rates of use continue to rise in others – was borne out using this new approach, which has proven capable of providing valuable indications which may help us to forecast future developments.
“For example it might be expected that PDU prevalence in Wigan will increase but that the rate of growth slow, and older users start to account for a larger proportion.
“PDU prevalence in the City of Manchester could decline because of current cessation rates amongst those that joined the population during the 1980s when incidence was at its peak. Movement of existing problem drug users from suburban and rural areas to urban areas could also explain the apparent decline in incidence rates, although this would not be consistent with accepted theories about how problem drug use spreads outwards from urban centres.
“Of course, Manchester and other 1980s hot spots continue to experience high levels of problem drug use, but it appears that situation could have stopped getting worse and may be starting to get better.”