Drug use among 25-year-olds in Ireland: results from the GUI study
by Seán Millar

Since 2006, the Growing Up in Ireland (GUI) national longitudinal study of children and young people has followed a cohort of children born in 1998. Five waves of interviews have been conducted with this cohort when they were aged 9, 13, 17–18, 20, and 25 years. This article presents findings on drug use from 3,380 interviews with the 25-year-old participants, which were conducted in 2023–24.1

 

Any drug use

Figure 1 shows the prevalence of illicit drug use among 25-year-olds in the GUI study. Cannabis was the most prevalent drug, with 56.6% of respondents stating that they had ever tried it. Just over one-fifth (21.4%) of 25-year-olds reported ever having tried cocaine, and cocaine usage in the last year was more common for men (24.3%) than for women (18.6%). The other most commonly reported drugs were ecstasy (10.7%), ketamine (9.7%), and magic mushrooms (6.9%).

 

Current cannabis use

One in seven (14.2%) respondents said they were current cannabis users, and more men (16.1%) than women (12.3%) indicated current cannabis use (see Figure 2). Those who had at least an NFQ Level 7 or equivalent qualification and those who did not reported comparable rates of cannabis use (14.3% of those with such a qualification compared with 14.0% of those without).

 

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Figure 1: Lifetime illicit drug use among 25-year-olds in Ireland, 2023–24

Source: GUI Ireland (2025)

LSD: lysergic acid diethylamide.

 

 

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Figure 2: Percentage of 25-year-olds who indicated current cannabis use, 2023–24

Source: GUI Ireland (2025)

 
  1. Central Statistics Office (2025) Growing Up in Ireland: Cohort ’98 at age 25 main results. Cork: Central Statistics Office. Available from: https://www.drugsandalcohol.ie/42586/