The latest results from the Adult Psychiatric Morbidity Survey (APMS) were published at the end of September. The survey provides data on the national state of mental health, and has been tracking drug use and dependence in the general population since 1993. The data indicates that drug dependence may be declining among young people. While the apparent fall doesn’t quite reach statistical significance, it is also evident in other data sources such as the Crime Survey for England Wales. It shouldn’t come as any surprise however; reports of drug use have been declining among children for the last decade according to the Smoking, Drinking and Drug Use survey.
So are young people really less likely to take drugs now – or are we just not asking them the right questions?
Efforts to measure use of NPS
Increasingly new psychoactive substances (NPS) have entered the drugs market. These substances, often referred to as ‘legal highs’, include mephedrone and synthetic cannabinoids, like Spice. They can have similar effects to traditional drugs like cocaine, cannabis and ecstasy, but were legal until the Psychoactive Substances Act came into effect in May 2016.
There have been attempts by survey researchers to measure the prevalence of these new substances in the population. For example, the school survey of Smoking, drinking and drug use among young people in England in 2014 captured awareness and use of legal highs. Pupils aged 11-15 were asked about ‘new substances that have the same effects as drugs like cannabis, ecstasy or cocaine’. Around half of pupils said they had heard of legal highs, and 2.5% of pupils had taken them at least once in their lifetime.
The Crime Survey for England and Wales 2014/15 also asked questions about use of generic rather than specific NPS in the last year. The survey found that the use of NPS appears to be concentrated among young people (particularly young men), as around 1 in 40 (2.8%) young people aged 16-24 took a NPS in the last year, compared to 1 in 100 (0.9%) of 16-59 year olds.
Defining new psychoactive substances
Although there have been several attempts to measure how widespread use of these new substances is nationally, they have all struggled with the same obstacle. The term ‘new psychoactive substances’ covers a wide variety of substances, often varying formulations of the same brand name, with substances quickly appearing on and disappearing from the market, so it is difficult to come up with a definitive list of NPS.
In an attempt to get around this, survey questions about NPS tend to refer to classes of drugs (such as ‘synthetic cannabinoids’ or hallucinogenic drugs) rather than specific substances. But this relies on the user knowing what they are taking so they can report it and many people using these substances may not actually know what they are taking. This makes it difficult not only to legislate NPS, but to research them.
The constraints of survey research
Another issue is that general population surveys tend not to include groups that we might expect to be more regular users of drugs than people in the general population. These include students who live in student accommodation, youth offenders, prisoners and the homeless. It is very rare for any of these groups to be included in national surveys for a number of reasons; they may not have an address, they are harder to reach, and they make up a very small percentage of the population so resources are prioritised to focus on the general population.
The fall in drug dependency among young people shown in APMS may be genuine but we should certainly be cautious. The apparent fall may actually reflect a failure to measure dependency on new substances. Before the next large national survey, we hope to have developed a more robust method for understanding how NPS fit into the bigger picture of drug use in the UK.
As NPS have only recently begun to be explored in general population surveys, those working in public health will have to wait and see whether they continue to increase in popularity.