Cannabis is the most widely used illicit drug in Europe and worldwide.1 While increased mortality rates are not associated with cannabis use, a number of very serious and long-term negative health problems are correlated with regular and long-term cannabis use. These include dependence, mental illness, cognitive impairment, cardiovascular disease and pulmonary disorders, including lung cancer and chronic obstructive pulmonary disease.2

Cannabis use in Ireland

The National Advisory Committee on Drugs and Alcohol (NACDA) published data on drug use in Ireland in 2016.3 The survey found that cannabis is the most commonly used illicit drug in Ireland in both genders and across all age groups, regardless of lifetime, last year or last month use. The results of the survey, completed in 2014/2015, are representative of the general population. Of note, 28% of all adults (15—64 years) had used cannabis in their life, with 4.4% of these having used in the month prior to completing the survey.3,4 This is higher than the European average lifetime cannabis use, which stands at 26.3%.5

In the last decade, an increasing trend in cannabis use is evident among Irish 15-34-year-olds, with 23.8% reporting cannabis use in their life in the 2002/2003 survey compared to 33.5% in this survey. A similar trend is seen in a number of other Northern European countries (Finland, Denmark, France, Germany and Sweden).7

Cannabis in first-time drug treatment entrants

As cannabis use has risen in the population so too has the number of people seeking specialised treatment for cannabis-related problems. Data on first-time entry into drug treatment services by cannabis users was published by EMCDDA-based Montanari and colleagues at Maastricht University in 2017.6 Information about people entering specialised drug treatment in 22 European countries, including Ireland, was included in the paper.* Specialised drug treatment was defined as people attending outpatient or inpatient centres, low threshold agencies, general practitioners (GPs) or treatment centres in prison in all participating countries. Irish data relevant to this paper were collected by the National Drug Treatment Reporting System (NDRTS) at the Health Research Board and routinely sent to the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA).

Cannabis was the problem drug used by approximately 30% of clients entering specialised drug treatment in 2014 across the 22 European countries (116,673 out of 400,125 admissions). Focusing on first-time treatment entrants alone, cannabis users accounted for 46% of all new entrants in 2014, with the highest numbers recorded in the UK, Germany, Spain and France. It is also important to note that the number of first-time cannabis treatment entrants has risen from 29% in 2003. In 2014, Ireland ranked eighth highest for the number of first-time cannabis treatment admissions (1,696).

In Europe, the annual number of first-time cannabis treatment entrants has increased each year, with an average annual percentage change (AAPC) of 6.1% between 2003 (32,178) and 2014 (67,444). While Ireland experienced fluctuations in the numbers of first-time cannabis treatment entrants between 2003 and 2006, there has been an increase in the number of admissions since 2006 (Figure 1). From 2003 to 2006, there was an annual percentage change (APC) of -6.23%, and from 2006 to 2015 there was an increase of 11.70% per year. Taken together, Ireland is above the European average with a 6.55% AAPC, between 2003 (982) and 2014 (1,696).

In terms of general admission to specialised drug treatment centres in Ireland (first-time and repeat entrants), cannabis accounted for 28% of overall admissions in Ireland in 2015, following heroin (41%).7

Importantly, the paper states that the increases in first-time cannabis admissions do not appear to be due to an overall rise in admission numbers for primary illicit drug problems. The authors also identify a number of potential reasons for the European-wide increase in first-time treatment entrants for cannabis use, including an increase in population awareness of the risk of cannabis use, an increase in the offer and availability of drug treatment across Europe, and an increase in the prevalence and potency of cannabis and synthetic cannabinoids, resulting in more people presenting with negative health outcomes. In addition, changes to drug policies towards more permissive or punitive approaches and an improvement in the level of reporting and monitoring are cited as potential reasons for the rise in the number of first-time cannabis treatment entrants.

Limitations of the study

These include population-related bias; potentially low reporting rates of GPs and other service providers; lack of a ‘synthetic cannabinoid’ option at the treatment level, which means that all cases are classed as cannabis; and the fact that this paper looks at cannabis alone, as opposed to entrants seeking treatment for polydrug use including cannabis in the list of problem drugs. A lack of quality control of the data is also cited as a limitation, as the data are collected in each country independently and then reported centrally to the EMCDDA.

Conclusions

This data highlight the growing trend of cannabis use in Ireland and Europe, as well as the increasing demand for treatment of cannabis-related problems. In terms of service provision, the needs of cannabis users are very different to those of opioid users, which have typically been the focus of public health interventions across Europe. This data should be used to inform policy-makers and service providers to help address this ever-growing problem.

2 Hall W, Renstrom M and Poznyak V (eds) (2016) The health and social effects of nonmedical cannabis use. Geneva: World Health Organization. https://www.drugsandalcohol.ie/25267/

3 National Advisory Committee on Drugs and Alcohol (NACDA) and Department of Health (UK) (2016) Prevalence of drug use and gambling in Ireland and drug use in Northern Ireland. Bulletin 1. Dublin: NACDA and Department of Health (UK). https://www.drugsandalcohol.ie/26364

4 Millar S (2017) Results from fourth general population survey on illicit drug use in Ireland. Drugnet Ireland, 60: 1—5. https://www.drugsandalcohol.ie/26697/

5 European Monitoring Centre for Drugs and Drug Addiction (2017) European drug report 2017: trends and developments. Luxembourg: Publications Office of the European Union. https://www.drugsandalcohol.ie/27401/

6 Montanari L, Guarita B, Mounteney J, Zipfel N and Simon R (2017) Cannabis use among people entering drug treatment in Europe: a growing phenomenon? European Addiction Research, 23(3): 113—121. https://www.drugsandalcohol.ie/27310/

7 European Monitoring Centre for Drugs and Drug Addiction (2017) Country drug report 2017: Ireland. Luxembourg: Publications Office of the European Union. https://www.drugsandalcohol.ie/27404/