Drug use: availability and prevalence

The true prevalence of drug use in a population can be difficult to ascertain due to the hidden nature of consumption, lack of taxation or sales data, and variable availability in routine data collection. Estimates of prevalence can be derived from surveys, police seizure records or drug testing in prisons. This section presents estimates of the availability of drugs, and prevalence of drug users in Scotland from various sources.

Drug seizures by Scottish police forces

The publication Drug Seizures and Offender Characteristics 2020/21 and 2021/22 (Tables 79.6Kb) presents data on the number of drug seizures made by the police in Scotland and the characteristics of individuals found in possession of drugs in 2020/21 and 2021/22. These statistics relate to substances controlled under the Misuse of Drugs Act 1971, which divides drugs into three classes (A, B and C). The drug classifications at the end of the reporting periods, to 31 March 2021 and 2022 respectively, have been applied to the data.

Due to changes in the data collection process, figures for drug supply and possession from 2014/15 onward are not directly comparable with figures produced for previous years. Since 2014/15, information from an annual random sample of 400 individuals found in possession of drugs has been used to estimate the number of seizures and quantities of drugs seized as a result of drug possession offences and as the basis for analysis of offender characteristics. This release uses figures from drug supply offences and samples of drug possession offences from 2014/15 onwards.

Key points:

In 201/22, for crimes of drug supply, drug production or illegal importation of drugs:
- The main Class A drugs seized by Police Scotland were, by weight, heroin (127 kg) and cocaine powder (64 kg). In addition, approximately 12,200 ecstasy-type tablets were seized. This was the lowest annual quantity of cocaine powder seized in the time series (Table 1b).
- The main Class B drugs seized by Police Scotland were herbal cannabis (1,467 kg) and cannabis resin (86 kg). 33,813 cannabis plants were also seized. This was the highest annual quantity of herbal cannabis seized in the time series (Table 2b).
- The main Class C substances seized by Police Scotland were benzodiazepines (approximately 4.8 million tablets). This was the second highest quantity of benzodiazepines seized in the time series (2019/20: 4.9 million tablets). It is likely that a significant proportion of those benzodiazepines were etizolam (Table 3b).
The total estimated quantity of drugs seized in 2021/22 (covering a minimum of 80% of all drug supply related crimes) was:
- Cocaine (class A): 70 kg
- Heroin (class A): 131 kg
- Herbal Cannabis (class B): 1,622 kg
- Benzodiazepines (class C): 4.9 million tablets (Table 6).
The majority (60%) of drug possession offences in 2021/22 involved offenders between 20 and 39 years old. Sixteen percent of offenders were under 20 years old and 24% were 40 years old or older (Table 7b).

Drug Misuse and Treatment in Scottish Prisons

From 2009/10 to 2018/19, Addiction Prevalence Testing (APT) was conducted across all Scottish prisons annually. During one month of the year, prisoners arriving in custody were voluntarily tested for the presence of illegal or illicit drugs. Similarly, those leaving custody during the month were tested to assess progress towards the 'reduced or stabilised' offender outcome.

In 2019 it was acknowledged by the Scottish Prison Service (SPS) that the APT process did not take account of the changing trends in drug use, and this was limiting the impact of APT in monitoring substance use and associated interventions. Due to this, SPS suspended APT to enable a review to be carried out with a view to improving the validity of testing and its connection to subsequent monitoring, intervention and action.

In 2021/22, Drug Trend Testing (DTT) replaced Addiction Prevalence Testing. DTT was carried out across 12 prisons in Scotland that receive direct admissions from court and includes private prisons. Prisons which do not receive admissions direct from court were not included in the testing study.

Key points:

Of the 769 tests carried out at prisoner reception in 2021/22, 77% were positive for drugs (which included drugs prescribed as part of a treatment programme), and 73% were positive for illegal drugs (including illegal use of prescribed drugs) (Data tables)
The drugs most commonly detected when entering prison in 2021/22 were cannabis (46% of tests) and cocaine (37% of tests). Opiates were found in 28% of tests and benzodiazepines in 28% of tests (Data tables).
Of the 259 tests carried out at prisoner liberation in 2022, 53% were positive for drugs (which included drugs prescribed as part of a treatment programme), and 29% were positive for illegal drugs (Data tables).
The drugs most commonly detected when leaving prison in 2021/22 were illegal buprenorphine (10% of tests), illegal benzodiazepines (10% of tests) and illegal opiates (7% of tests). Illegal methadone was found in 6% of tests (Data tables).
Illegal buprenorphine was the only illicit drug more prevalent in the tests carried out at prisoner liberation (10%), than in those carried out at prisoner reception (8%) (Data tables).
As part of the revised DTT process, amphetamines and methamphetamines were removed from the testing panel and two new substances were added: pregabalin and gabapentin. Figures show that 9% of those tested on admission to custody were positive for pregabalin and 2% for gabapentin. On liberation the figures were 5% and 1% respectively (Data tables).

Previous year's APT findings can be found here:

The Scottish Prisoners Survey 2017 was undertaken in each of the 15 Scottish prisons, with a survey form sent to all prisoners. The response rate fell below 50% for the first time in 2017, with an overall return rate of 46% (55% in 2015). Of the respondents, 93% were males and the average age was 33 years. Eighty percent of respondents were convicted and 20% were on remand at the time of completing the 2017 prisoner survey.

Key points:

There was a slight decrease in the percentage of prisoners who stated that they were under the influence of drugs at the time of their offence from 40% in 2015 to 38% in 2017. Fifteen percent of prisoners reported that they committed their offence to get money for drugs (17% in 2015) (Main Bulletin-Drug use section).
The percentage of prisoners who stated their drug use was a problem for them outside prison decreased from 38% in 2015 to 36% in 2017. Around one fifth of prisoners (19%) were receiving treatment for drug use before they were imprisoned (21% in 2015) (Main Bulletin-Drug use section and Change over time section).
In 2017, 39% of prisoners reported that they had used illegal drugs in prison at some point; a decrease from 43% in 2015. Of these, four in five (83%) stated that their drug use had changed during their current period in prison. Most individuals reporting a change in their drug use (61%) said it had stopped or decreased, 13% reported it had increased, 14% reported their drug use had remained the same but they used different drugs and 13% stated that they had started using drugs in prison (Main Bulletin – Drug use section).
In 2017, just over one fifth (22%) of prisoners reported using drugs in prison in the month prior to the survey (24% in 2015). Among those who used drugs, cannabis (64%), buprenorphine (Subutex) (51%), benzodiazepines (46%) and heroin (42%) were the most commonly used substances. In percentage terms, usage of all of these drugs increased from 2015 to 2017. The percentage taking heroin in the month prior to the survey increased from 33% of recent drug users in 2015 to 42% in 2017 (Main Bulletin - Figure 4).
Five percent of prisoners reported injecting drugs in prison, with 1% stating they injected in the month prior to the survey; these percentages were lower than in 2015 (6% and 2% respectively). Among people who injected drugs in the past month, 50% (n=12) reported sharing injecting equipment. Heroin was the most commonly injected drug among this group (Main Bulletin-Drug use section and Change over time section).
One-fifth of prisoners (20%) reported being prescribed methadone in prison (unchanged since 2015: 20%). Of these, just under half were on a maintenance dose (48%), almost a third (32%) were on a stabilising dose and a fifth (21%) on a reducing dose. More than one in four prisoners prescribed methadone (26%) stated that they had taken another prisoner’s prescribed medication while in prison (Main Bulletin-Drug use section and Change over time section).
Approximately one in five (18%) prisoners reported having ever been supplied with take home naloxone and 8% had been supplied with take home naloxone in the last 12 months. Where a prisoner had received naloxone in the last year, 63% received it in prison and 67% received it in the community. A minority (7%) of prisoners had administered naloxone to someone else and 7% had had it administered to them by someone else (Main Bulletin – Table 5).
In 2017, 18% of prisoners reported using ‘novel’ or ‘new’ psychoactive substances (NPS)/legal highs at any point prior to imprisonment (a decrease from 27% in 2015 – figure not included in 2017 report) (Main Bulletin-New Psychoactive Substances section). Of these, 70% had used synthetic cannabis, 46% used stimulants, 28% used a ‘downer’, 22% used a hallucinogen and 11% reported being unsure what they were using (Main Bulletin - Figure 5).
Around one-fifth of prisoners (18%) reported using NPS/legal highs in prison (an increase from 11% in 2015 – figure not included in 2017 report) (Main Bulletin- New Psychoactive Substances section). Of these, almost four-fifths (78%) reported using synthetic cannabis, 23% used hallucinogens, 17% used stimulants, 16% reported that they had used a ‘downer’ and 12% were unsure what they had used (Main Bulletin - Figure 6).
Two in five prisoners (39%) reported being assessed for drug use when entering prison (the same percentage as in 2015). More than one quarter (28%) of prisoners said they have been given the chance to receive treatment for drug use (the same percentage as in 2015) and one quarter (25%) reported that they have received help/treatment for drug use during their sentence (28% in 2015) (Main Bulletin – Table 6).
Two-fifths of prisoners (40%) stated they would accept help for a problematic drug use in prison or stated they would accept help on the outside (38%). Less than one quarter of prisoners (22%) were concerned that their drug use would be problematic for them upon release (24% in 2015) (Main Bulletin – Table 6).

Illicit drug use among adults

Information on the extent of illicit drug use is derived from surveys of samples of the general population. Collecting accurate information on illicit drug use is notoriously difficult because of its hidden and illegal nature. Surveys vary in terms of the number of participants and the degree to which they are representative of the wider population and, therefore, some caution is needed in interpretation of estimates.

The Scottish Crime and Justice Survey (tables) is one source of information on illicit drug use among adults. The latest results presented below are from two survey years of the SCJS combined (2018/19 and 2019/20). This is referred to throughout the section as 2018/20. Note however that the illicit drugs data for previous years refers to individual years (the last being 2017/18).

Key points:

In 2018/20, 9.7% of respondents (aged 16 years and over) had used illicit drugs (excluding non-illicit drugs and prescription only painkillers), compared with 7.4% in 2017/18 (Page 155, Table 4.01a: previous year’s figures not shown in table).
Higher levels of drug misuse were reported among males than females. In 2018/20, 13.1% of males aged 16 and over reported illicit drug, compared to 6.5% of females. (Table 4.01a).
Individuals aged 16-24 were most likely to report using drugs in 2018/20 (23.5%), compared with 14.7% of those aged 25-44, 6.8% of 45-59-year-olds and 1.6% of those aged 60 or older (Table 4.01a).
Individuals living in the 15% most deprived areas were more likely to report using drugs in 2018/20 (15.1%), compared to those living in the rest of Scotland (8.9%) (Table 4.01c).
In 2018/20, the most commonly reported illicit drug used was cannabis (7.9% of adults), followed by cocaine (3.0%) and ecstasy (1.6%) (Table 4.01a).

Illicit drug use among children

A key source of information on illicit drug use among children and young people is the Health and Wellbeing Census Scotland: 2021/22 (Tables) published in February 2023. This was the first Health and Wellbeing (HWB) Census and it replaced the Scottish Schools Adolescent Lifestyle and Substance Use Survey (SALSUS).

The HWB Census was undertaken by 16 local authorities in Scotland between October 2021 and June 2022. The results presented below are aggregated findings and are not weighted to population totals.

Some key points from the 2021/22 survey, which focused on 15-year-olds (S4 pupils) are summarised below:

Of the 25,910 S4 pupils from the 16 participating local authorities, 11,738 responded to the survey, of which 7,589 (29.3% response rate) completed the Substance Use Questionnaire.
Of the 7,589 S4 pupils who completed the Substance Use Questionnaire, 9.6% reported ever taken illegal drugs, 80.9% had not, 4.3% preferred not to say and 5.3% of responses were unknown (Table 16a).
By sex, 11.3% of male and 7.7% of female 15-year-olds said they had ever taken illegal drugs at some point (Table 17a). Reported drug use was fairly similar across deprivation quintiles (SIMD 1 (most deprived) to SIMD 5 (least deprived)) with 8.9% to 9.0% of 15-year-olds in each quintile reporting they had ever taken illicit drugs (Table 18a).
Of the 15-year-olds who had ever taken illegal drugs, 22.4% had only taken drugs once, 19.4% took drugs at least once a week or more, 16.5% had taken drugs once or twice a month and 14.6% said they no longer take drugs (Table 16b).
Of the 257 pupils (3.4% of respondents) who had taken drugs in the last month, the most commonly used illicit drug reported was cannabis (94.6%), followed by cocaine (45.5%), ketamine (35.8%) and ecstasy (34.6%) (Table 16c). As a percentage of all respondents, this was equivalent to 3.2% of 15-year-olds using cannabis, 1.5% using cocaine, 1.2% using ketamine and 1.2% using ecstasy in the past month.

Estimated prevalence of problem drug use

The group of drug users who are most likely to experience health and social problems are those who misuse opiates (primarily heroin) and/or benzodiazepines (for example, diazepam and etizolam). It is this group who are also most vulnerable to acquiring communicable diseases (such as HIV and hepatitis primarily through sharing injecting equipment) and have a high risk of imprisonment due to drug-related or acquisitive offences.

In March 2024, Public Health Scotland, in collaboration with the University of Bristol and Glasgow Caledonian University, published the first in a new series of reports on the 'Estimated prevalence of opioid dependence in Scotland’ (Tables). All estimates in this report were calculated using a recently developed statistical modelling approach, 'Multi-Parameter Estimation of Prevalence' (MPEP). MPEP brings multiple linked data sources together to make inferences about the size of the population and its prevalence. In this instance, the model used linked PHS-held administrative data on opioid agonist therapy (OAT) prescriptions, drug-related deaths and overdose hospital admissions from the Scottish Public Health Drug Linkage Programme.

This report estimates the prevalence of opioid dependence among people aged 16 to 64 living in Scotland. Estimates for Scotland and three NHS Boards (Greater Glasgow and Clyde, Lothian and Tayside) are provided, stratified by sex (female, male), age group (15 to 34, 35 to 49 and 50 to 64 years) and financial year (2014/15 to 2019/20).

Estimates are presented with 95% credible intervals (CrI) to represent the extent of uncertainty around each finding. All population size estimates have been rounded to the nearest hundred. See the Glossary in the main report for more information about any technical terms used.

Key points:

In 2019/20:

The estimated number of people with opioid dependence in Scotland was 47,100 (95% Credible Interval (CrI) 45,700 to 48,600). This represented an estimated prevalence of 1.32% (95% CrI: 1.28% to 1.37%) of 15- to 64- year-olds (Table 1).
Among males aged 15 to 64 years, the prevalence of opioid dependence was estimated to be 1.85% (95% CrI: 1.79% to 1.91%). Among females aged 15 to 64 years, it was estimated to be 0.82% (95% CrI: 0.79% to 0.85%) (Table 2).
The prevalence of opioid dependence was estimated as 0.87% (95% CrI: 0.82% to 0.94%) among people aged 15 to 34 years, 2.67% (95% CrI: 2.59% to 2.76%) among people aged 35 to 49 years, and 0.65% (95% CrI: 0.62% to 0.69%) among people aged 50 to 64 years (Table 3).
By NHS Board, the estimated prevalence of opioid dependence was 1.77% (95% CrI: 1.69% to 1.85%) in Greater Glasgow and Clyde, 1.25% (95% CrI: 1.18% to 1.33%) in Lothian and 1.36% (95% CrI: 1.28% to 1.45%) in Tayside (Table 1).
An estimated 61% of people with opioid dependence received opioid agonist therapy (OAT) at some point during the year, % had received OAT at some point during the period 2015/16 to 2019/20 (Table 5).

The overall prevalence of opioid dependence was relatively stable from 2014/15 to 2019/20 (Table 1). Over the same time period, there was a reduction in opioid dependence among 15- to 34-year-olds and an increase among 50- to 64-year-olds (Table 3).

Although injecting prevalence was not reported in the 2024 publication, an estimate was provided in a previous prevalence report based on 2006 data (Hay et al, 2009).

In 2006, there were an estimated 23,933 people injecting opiates and/or benzodiazepines. The highest drug injecting prevalence rates by council area were identified in Inverclyde at 1.63% (95% CI 1.30-2.07%) of the population aged 15-64, followed by Aberdeen City and Glasgow City with prevalence rates of 1.56% (95% CI 1.25-1.98%) and 1.35% (95 CI 1.08-1.72%) respectively.

The estimated prevalence of problem drug use in Scotland among 15-64-year-olds is also included in the ScotPHO Drugs Profile (for males, females and both genders), so can be explored by NHS Board and ADP area.

Availability

Assessing the scale of the drug market in Scotland is even more difficult given its illicit nature, although a study published in 2009 (Assessing the Scale and Impact of Illicit Drug Markets in Scotland) provides initial estimates of the size and value of the illicit drugs market and estimates of the social and economic cost of illicit drug use in Scotland for the year 2006. The total value of the illicit drugs market was estimated at around £1.4bn. Heroin held the largest share of the market with 39% of the market, with cannabis holding a 19% share, the second largest. Problem drug users held the largest percentage share of the total market (63%).

Please note: If you require the most up-to-date data available, please check the data sources directly as new data may have been published since these data pages were last updated. Although we endeavour to ensure that the data pages are kept up-to-date, there may be a time lag between new data being published and the relevant ScotPHO web pages being updated.