The first survey on drug use in the general population was carried out in Ireland in 2002/3. The results were jointly published by the National Advisory Committee on Drugs (NACD), now the National Advisory Committee on Drugs and Alcohol (NACDA), and the Drug and Alcohol Information and Research Unit. The survey was repeated in 2006/7 and in 2010/11.¹ In 2014, the NACDA commissioned IPSOS MRBI to conduct the Ireland and Northern Ireland drug prevalence survey 2014/15.²

The 2014/15 survey followed best practice guidelines recommended by the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). The questionnaire, based on the European Model Questionnaire, was administered in face-to-face interviews with respondents aged between 15+ years. A sample comprising all households throughout the island of Ireland was randomly selected to participate and fieldwork began in September 2014 and was completed in May 2015. Of the household members contacted, 7005 agreed to take part. The sample was weighted by gender, age and region to ensure that it was representative of the general population. The main measures were lifetime (ever used) use, use in the last year (recent use) and use in the last month (current use).

Use of any illegal drugThe proportion of respondents aged 15‒64 years who reported using any illicit drug in their lifetime has increased from 19% in 2002/3 to almost 31% in 2014/15 (Figure 1). There has also been an increase when compared to the 2010/11 study (27%). Similarly, last year and last month prevalence of any illegal drug use has increased since the previous survey; from 7% to 9% and 3% to 5%, respectively. Any illegal drug refers to the use of cannabis, ecstasy, cocaine power, magic mushrooms, amphetamines, poppers, LSD, new psychoactive substances (NPS), solvents, crack and heroin.

 Illicit drug use was more prevalent in males, and was also greater among young adults, with almost 9% of persons aged 15‒34 years having reported illegal drug use within the previous month (compared to 5% in 2010/11). Results from the 2014/15 survey indicated that the most commonly used illicit substances in Ireland, based on last month prevalence, were cannabis (4%), ecstasy (1%) and cocaine (0.5%).

  Cannabis use

Findings revealed that 28% of the population (15‒64 years) had used cannabis at some point in their lives; 8% reported use in the year prior to the survey; and 4% indicated use in the preceding month. All of these rates are higher than those recorded in previous surveys within Ireland (Figure 2).

Similar to earlier studies, rates of cannabis use were greater among men than women: (36% vs 20%) lifetime use; (11% vs 4%) last year use; and (7% vs 2%) last month use. Since 2002/3, lifetime rates of cannabis use among males have increased by 61% and last month use by 94%. Lifetime use of cannabis among females has also increased (20% in 2014/15 vs 12% in 2002/3). However, last month prevalence in women has remained relatively stable over time.

The prevalence of cannabis use was noticeably higher among young adults (15‒34 years). Lifetime rates were similar to those reported in 2010/11 (34%). Last year and last month prevalence rates were higher than those recorded in the previous survey (14% vs 10% and 8% vs 5%), and the proportion of young adults who classified themselves as current users of cannabis has almost doubled since 2002/3. Approximately 13% of males and 6% of females aged 15‒24 years indicated that they had used cannabis in the month prior to the survey. Lifetime, last year and last month rates of cannabis use among adults aged 35‒64 years were 24%, 3% and 2%, respectively.

Cocaine use

Lifetime cocaine use has increased when compared to 2010/11 (Figure 3). The percentage of respondents aged 15‒64 years who reported using cocaine (including crack) at some point in their lives increased from 7% to 8%. The proportion of young adults (15‒34 years) who reported using cocaine in their lifetimes has also increased from 9% to 11%.

As was observed in previous studies, more men reported using cocaine in their lifetimes compared to women (11% vs 5%). However, although the lifetime rate of cocaine use among persons aged 15‒64 years and young adults aged 15‒34 years has more than doubled since 2002/3, the percentage of respondents reporting current use of cocaine has remained relatively unchanged across surveys.

 Ecstasy use

In Figure 4, significant increases in lifetime and last year prevalence of ecstasy use were observed in persons aged 15‒64 years (7% to 9% and 0.5% to 2%, respectively). Fourteen per cent of young adults (15‒34 years) claimed to have tried ecstasy at least once in their lifetime, with over 4% having used it within the last year (vs 0.9% in 2010/11) and 2% indicating current use (vs 0.1% in 2010/11). Almost 10% of males and 4% of females aged 15‒24 years reported using ecstasy within the previous year, while current use was 4% (males) and approximately 3% (females) for the same age category.

 Previous findings from the 2010/11 survey had suggested a decline in the use of ecstasy among younger Irish adults when compared to earlier studies. This was possibly due to the increased use of NPS sold in head shops and online.³

New psychoactive substances (NPS)

In 2014/15, the lifetime prevalence of NPS use among respondents aged 15‒64 years was approximately 4%, while last month prevalence was less than 1%. In male adults aged 35-44 years, and those aged 45‒54, lifetime prevalence rates were 3% for both. For females, the corresponding rates were 1.2% and 0.9%, respectively. Last month prevalence of NPS use for both age categories was less than 1% in both genders.

Last year prevalence of NPS use was included as a drug category for the first time in the 2010/11 NACDA drug prevalence survey. In contrast to trends observed with other illicit substances, data from the 2014/15 study demonstrate a reduction in the use of NPS in the Irish population in both genders (Figure 5). The percentage of male and female young adults aged 15‒24 years who indicated current use of NPS was also less than 1%.

The low prevalence of current NPS use among younger Irish adults, and decreasing trends in NPS use among respondents aged 15‒64 years of both genders, may be as a result of the Criminal Justice (Psychoactive Substances) Act 2010, which came into effect in August 2010. The Act made it an offence, punishable by up to five years’ imprisonment, to sell or supply for human consumption substances which are not specifically proscribed under the Misuse of Drugs Acts, but which have psychoactive effects.⁴

Nevertheless, despite a decline in the use of NPS, the results from the 2014/15 survey indicate an increase in the use of illicit substances within Ireland. This is largely due to an increase in the use of cannabis and ecstasy among younger adults, and in particular young males.

Although opioids were included as a drug category in this study, the prevalence of heroin use was low, as the Ireland and Northern Ireland drug prevalence survey 2014/15 is a general population survey. Thus, persons who do not normally reside in private households have not been included. A national three-source capture-recapture (CRC) study to provide statistically valid estimates of the prevalence of opiate drug use in the national population was commissioned by the NACDA and undertaken in 2001⁵ and 2006.⁶ The three data sources used were the Central Treatment List (of clients on methadone), the Hospital In-Patient Enquiry (HIPE) scheme, and Garda PULSE data. A third study using the CRC method was commissioned in 2014, and a final report is due to be published shortly.

Seán Millar

___________________

1. National Advisory Committee on Drugs (NACD) and Public Health Information and Research Branch (PHIRB) (2011) Drug use in Ireland and Northern Ireland: first results from the 2010/11 Drug Prevalence Survey. Bulletin 1. Dublin: NACD and PHIRB. http://www.drugsandalcohol.ie/16353
2. National Advisory Committee on Drugs and Alcohol (NACDA) and Department of Health UK (2016) Prevalence of drug use and gambling in Ireland and Northern Ireland. Bulletin 1. Dublin: NACDA and Department of Health UK. http://www.drugsandalcohol.ie/26364/

www.health-ni.gov.uk[AW2] 

1. Long J (2012) Results from the third general population survey in Ireland. Drugnet Ireland, 40: 6‒8. http://www.drugsandalcohol.ie/16866/
2. Criminal Justice (Psychoactive Substances) Act 2010. Available online at http://www.irishstatutebook.ie/eli/2010/act/22/enacted/en/html
3. Kelly A, Carvalho M, Teljeur C (2003) Prevalence of opiate use in Ireland 2000‒2001: a 3-source capture recapture study: a report to the National Advisory Committee on Drugs Sub-Committee on Prevalence. Dublin: Stationery Office. http://www.drugsandalcohol.ie/5942/
4. Kelly A, Teljeur C, Carvalho M (2009) Prevalence of opiate use in Ireland 2006: a 3-source capture recapture study: a report to the National Advisory Committee on Drugs. Dublin: Stationery Office. http://www.drugsandalcohol.ie/12695/