Introduction
Cannabis is the most widely used illicit substance among adolescents and is a significant contributor to global disability-adjusted life years (Engelgardt et al., Reference Engelgardt, Krzyżanowski, Borkowska-Sztachańska, Wasilewska and Ciucias2023; Degenhardt et al., Reference Degenhardt, Whiteford, Ferrari, Baxter, Charlson, Hall, Freedman, Burstein, Johns, Engell, Flaxman, Murray and Vos2013). Cannabis use typically begins in adolescence, with youth aged 12–17 years accounting for two-thirds of the new cannabis users (Meyers and Dick Reference Meyers and Dick2010). Adolescence marks a period of increased autonomy and risk-taking, that can influence how health and health-related behaviours develop. The aetiology of drug use, specifically cannabis use in adolescence is multifactorial and involves a complex interplay between biopsychosocial determinants (Meyers and Dick Reference Meyers and Dick2010).
Data from the Growing Up in Ireland study found that 10% of 17–18 year olds reported currently smoking cannabis occasionally or more than once per week (Mangan-Ryan et al., Reference Mangan-Ryan, McNamara, O’Mahony, Murphy and O’Reilly2020; O’Mahony et al., Reference O’Mahony, Murray, Williams, McNamara, O’Reilly and McClintock2021). The 2019–20 National Drug and Alcohol Survey (NDAS) found that past-month cannabis use among 15–24-year-olds had increased from 5.6% in 2002–3 to 6.8% in 2019–20 (Mongan et al., Reference Mongan, Millar and Galvin2021; Dunne Reference Dunne2021). The 2019 European Schools Project on Alcohol and Other Drugs (ESPAD) survey found that past-month cannabis use among 15–16-year-olds in Ireland (9%) was higher than the average across participating ESPAD countries (7.1%). Most adolescents participating in the 2019 ESPAD study did not perceive significant risk in cannabis use, and 42% reported that it would be ‘fairly’ or ‘very easy’ to get cannabis if they wanted to (ESPAD Group, 2020).
Evidence has indicated that long-term use has the potential to lead to addiction, with 1 in 3 adolescent regular users (weekly or daily) becoming addicted (Leung et al., Reference Leung, Chan, Hides and Hall2020). The 2019–20 NDAS Study found 19.6% of young people who had used cannabis in the past year met the criteria for Cannabis Use Disorder (Mongan et al., Reference Mongan, Millar and Galvin2021; Dunne Reference Dunne2021). Cannabis use also has the potential to exacerbate mental health concerns such as psychosis. Cannabis users are at a 3–4-fold increased risk of developing an acute psychosis, with evidence that this association is increased to 5–6-fold with early use of high potency cannabis (Di Forti et al., Reference Di Forti, Marconi, Carra, Fraietta, Trotta, Bonomo, Bianconi, Gardner-Sood, O’Connor, Russo, Stilo, Marques, Mondelli, Dazzan, Pariante, David, Gaughran, Atakan, Iyegbe, Powell, Morgan, Lynskey and Murray2015; Marconi, et al., Reference Marconi, Di Forti, Lewis, Murray and Vassos2016). In addition, the number of people entering cannabis addiction treatment has increased in Ireland (Millar et al., Reference Millar, Mongan, O’Dwyer, Long, Smyth, Perry and Galvin2021). Cannabis-related psychiatric admissions for people aged 15–34 in Ireland increased by 140% between 2011 and 2017 (Smyth et al., Reference Smyth, O’Farrell and Daly2019) and have remained at this elevated level since then. In 2021, the majority (88.1%) of those entering addiction treatment under 18 years of age, reported cannabis as their primary problem drug (HRB National Drugs Library 2024). Furthermore, the adverse effects associated with cannabis use are more likely to present if use begins at a young age, impacting aspects of life aside from physical and mental health such as social, educational and professional achievements (Gobbi et al. Reference Gobbi, Atkin, Zytynski, Wang, Askari, Boruff, Ware, Marmorstein, Cipriani, Dendukuri and Mayo2019; Carver et al., Reference Carver, McCulloch and Parkes2021).
Despite the above evidence of increased risks, adolescents continue to use cannabis. Research has demonstrated various continuation factors, such as boredom relief, appetite increase, sleep improvement and increased social opportunities (Lehman et al., Reference Lehman, Thompson, Adams, Hawes, Pacheco-Colón, Granja and Paula2023). However, qualitative data suggests alternative explanations such as personal factors including low self-esteem and insecurity, or family problems including interfamilial violence or bullying (González-Cano-Caballero et al., Reference González-Cano-Caballero, Torrejón-Guirado, Cano-Caballero, Mac Fadden, Barrera-Villalba and Lima-Serrano2023). Other salient factors may contribute to increased cannabis use in adolescences, including recent media coverage involving the decriminalisation of cannabis and the potential use of cannabis in medical treatment (Cohn et al., Reference Cohn, Alexander, Ehlke, Smith, Lowery, McQuoid and Kendzor2023). All of which have contributed to a growing societal acceptance of cannabis use and an incorrect perception by some that its use is without risk (Willoughby et al., Reference Willoughby, Hust, Li and Couto2023).
Risk and protective factors for cannabis use have previously been grouped into different domains including individual, familial and community or individual, interpersonal, community, societal and multilevel (Hawkins et al. Reference Hawkins, Catalano and Miller1992; Butler et al., Reference Butler, Romano and Leatherdale2022; Nawi et al., Reference Nawi, Ismail, Ibrahim, Hassan and Manaf2021). Protective factors within these domains can include mindfulness, harmful beliefs related to substance use, personal health goals, parental drug awareness, and structured school related activities. However research has indicated the strongest protective factors include family norms and structured leisure times (Woodward et al., Reference Woodward, Smith, Mann, Kristjansson and Morehouse2023).
Risk factors can include increased impulsivity, deficits in regulatory ability, screen time, decreased beliefs related to substance use harms, and low parental education. Recent research has demonstrated significant risk can be associated with two key factors; peer substance use and peer substance use norms (Woodward et al., Reference Woodward, Smith, Mann, Kristjansson and Morehouse2023). Mental health concerns such as depression and anxiety are also associated with an increased risk of substance use, particularly during the period of COVID-19 (Libuy et al., Reference Libuy, Ibáñez, Araneda, Donoso and Contreras2024; Mehra et al., Reference Mehra, Rup, Wiese and Watson2023). Gender can be a risk factor, as adolescent males (8.5%) appear to be more likely than females (5.8%) to use cannabis (Doyle et al., Reference Doyle, Sunday, Galvin and Mongan2022). However more research is required as the available evidence is mixed regarding gender and potential intervention pathways (Tinner et al., Reference Tinner, Palmer, Lloyd, Caldwell, MacArthur, Dias, Langford, Redmore, Wittkop, Watkins, Hickman and Campbell2022).
The rationale for identifying risk and protective factors for cannabis use in adolescents is to provide national policymakers and local service providers with up-to-date and identifiable targets for prevention and early intervention. Identifying protective factors is important as the majority of research to date has focused on identifying risk factors, many of which are difficult to behaviourally modify.
A key goal is to delay the onset of substance use, to prevent possible harm to the adolescent development, and to reduce the risk of problematic substance use later in life (Department of Health 2017).
Therefore, the aim of this study was to examine individual, familial, peer, school and community factors associated with cannabis use in a general population sample of adolescents in Ireland.
Methods
Study design
This study involves analysis of cross-sectional data collected in November 2021 as part of the Planet Youth Programme in the East of Ireland (Planet Youth Partner Ireland 2021). This programme is based on the Icelandic Prevention Model, an international evidence-based primary prevention model developed by the Icelandic Centre for Social Research and Analysis at Reykjavik University (Kristjánsson et al., Reference Kristjánsson, Mann, Sigfusson, Thorisdottir, Allegrante and Sigfúsdóttir2020). The programme was initially created in the early 1990s to reduce youth substance use rates in Iceland, and its impact has been profound (Sigfúsdóttir et al., Reference Sigfúsdóttir, Thorlindsson, Kristjánsson, Roe and Allegrante2009). The Icelandic Prevention Model is based on the perspective that adolescent health-related behaviours are part of a young person’s broader lifestyle, and health is viewed in its social context. It is a collaborative upstream model designed to identify, and subsequently influence, risk and protective factors within the community (school, peer, family networks) related to adolescent substance use (Halsall et al., Reference Halsall, Lachance and Kristjansson2020). A core element of this model is to identify local risk and protective factors through repeated surveys, around which prevention strategies can be developed (Carver et al., Reference Carver, McCulloch and Parkes2021).
Setting
The survey was undertaken in North Dublin, Cavan and Monaghan. These regions encompass a mix of urban, suburban and rural areas. All schools and YouthReach centres (official programme for early school leavers) in these areas were invited to participate.
Participants
The target population for the Planet Youth study were students in their fourth/fifth year of secondary school, aged 15–16 years old (with some schools including a wider age range). In schools that agreed to participate, students and parents were given information about the survey and invited to opt-out if they wished.
Procedure
Surveys were completed during school hours September–November 2021. All surveys were carried out on portable tablets. All surveys were undertaken during school hours, in classrooms and ranged from 45 minutes to 1 hour. Research subjects were anonymous.
Outcome: cannabis use
Participants were asked, ‘During the last 30 days: How often have you used cannabis products?’ The response categories ranged from ‘Never’ to ‘40 times or more’. For the purposes of the analysis and due to small cell issues in several outcome levels (n < 30), those responding ‘Never’ were categorised as current non-users (reference) and those providing any other response were categorised as current users.
Predictors
All predictor factors were self-reported by the adolescent and were grouped into sociodemographic, individual, family, peer group, and school/community factors.
Sociodemographic factors
Gender
Participants reported their gender as male, female, non-binary and/or transgender, or ‘prefer not to say’ which were categorised as male (reference), female and ‘other’ for the purposes of the analysis.
Socio-economic status
Maternal education level was included as an indicator of familial socio-economic status and had 3 levels: college/university (reference), secondary school/primary school, or unknown.
Individual factors
Mental health
Participants rated their mental health on a likert scale which was categorised to ‘very good/ good/okay’ (reference) and ‘very bad/ bad’.
Other substance use
Current use of alcohol, cigarettes and e-cigarettes referred to the binary use of each substance (yes/no (reference)) in the past 30 days.
Perception of cannabis
Participants reported their perception of cannabis as ‘harmful’ (reference), ‘not harmful’ or ‘unsure’.
Family-related factors
Level of parental supervision was measured as a continuous cumulative score from two items: ‘My parents know who I am with in the evenings’ and ‘My parents know where I am in the evenings’. A total possible score for parental supervision was 10. The five response categories ranged from ‘strongly agree’ to ‘strongly disagree’ and were scored from 1 to 5 with higher scores indicating less parental supervision.
Parental attitudes to cannabis
Participants reported how their parents would react if they used cannabis substances. Responses were dichotomised into ‘[Totally] Against’ (reference) or ‘A bit against/don’t care’.
Parent-peer knowledge referred to the strength of social links between the participants peer group and parents. Participants responded to ‘My parents know my friends’ and ‘My parents know my friend’s parents’ on a 5 point scale from ‘strongly agree’ to ‘strongly disagree’, which were also converted to numeric scores and summed to form a total score with higher scores indicating lower levels of parental-peer knowledge.
Peer group related factors
Peer cannabis use was measured as at least one friend using cannabis.
Peer pressure to use cannabis was measured by participants’ agreement with the statement ‘Sometimes you need to smoke cannabis, so you’re not left out of a group of friends’. Responses were dichotomised to ‘No’ (reference) and ‘Yes’.
School and community factors
Participation in team sports was included as a 3-category frequency variable with options ‘Almost never’ (reference), ‘1-3 times per week’, and ‘≥=4 times per week’. S
School engagement was calculated from participants’ level of frequency of the following experiences: ‘I find the schoolwork pointless’, ‘I find schoolwork boring’, ‘I am poorly prepared for classes’, and ‘I feel l do not put enough effort into my schoolwork’. Responses were converted to numeric scores ranging from 1 (‘Almost always’) to 4 (‘Almost never’), and were summed to form a total score, with higher scores indicating higher levels of school engagement.
Measures of parental supervision, parent-peer knowledge, and school engagement are consistently incorporated in previously published Icelandic Prevention Model research (Sigfúsdóttir et al., Reference Sigfúsdóttir, Thorlindsson, Kristjánsson, Roe and Allegrante2009; Kristjánsson et al., Reference Kristjansson, Lilly, Thorisdottir, Allegrante, Mann, Sigfusson, Soriano and Sigfusdottir2021; Kristjánsson and Sigfúsdóttir Reference Kristjánsson and Sigfúsdóttir2009; Kristjánsson et al., Reference Kristjánsson, Sigfúsdóttir, Thorlindsson, Mann, Sigfusson and Allegrante2016).
Data analysis
Specific respondents were removed as part of the data cleaning process in Reykjavik to ensure survey accuracy. The criteria for elimination included insufficiently completed questionnaires i.e., insufficient participant demographic data, reporting the use of a fictitious drug or reporting to have tried every substance 40 times or more (Kristjánsson et al., Reference Kristjánsson, Mann, Sigfusson, Thorisdottir, Allegrante and Sigfúsdóttir2020).
Statistical analysis was performed using Stata statistical software, version 18 . Youthreach centres taking part in the survey were merged to form an overarching ‘Youthreach’ school unit for each county, creating a single combined unit for the purposes of the analysis. Descriptive analyses were conducted to characterise cannabis users and non-users’. Prevalence calculations were based on self-reported cannabis use in the last 30 days.
Associations between cannabis use and sociodemographic, familial, peer, school and community factors were explored using mixed-effects logistic regression models, unadjusted and the multivariable models were adjusted for all other factors included in the analysis. School location was modelled as the random effect. Multicollinearity was tested for using variance inflation factors. Assumptions were assessed using the Box-Tidwell test for the purposes of the analysis. Odds ratio, 95% confidence intervals, and two-tailed P-values were calculated for all analyses, with the significance level set at 5% (p = < 0.05).
Results
Characteristics of the sample
A total of 45 schools were invited to participate in the survey, with 40 schools deciding to participate (88.9%). Over 5,000 survey responses were anticipated, with 4,404 valid surveys returned, as shown in Table 1, resulting in a final student response rate of 80.1%. There were 4,404 15–16-year-olds eligible for inclusion in this study, 4,072 of which had given information on current cannabis use (92.5%). Overall, 7.3% (n = 302) were current cannabis users. When looking at current users by county, Cavan had 8.5% reporting current cannabis use, Monaghan had 5.6% and North Dublin had 7.6%. See Table 1 for school and student response rates by county (Table 1) .
Table 1. School and student response rates for the 2021 planet youth survey
Results of multivariable logistic regression
Sociodemographic factors
The results of the univariable and multivariable logistic regression models are shown in Table 2 and indicate there were no significant associations between gender or maternal education and cannabis use.
Table 2. Descriptive statistics for cannabis and non-cannabis users, and the ability of various factors to distinguish groups (unadjusted and adjusted). Percentages refer to proportion of cannabis users/non-users
Adjusted effect means that the OR was adjusted for all other factors in the multivariable analysis. 3,620 participants were included in the adjusted analysis (263 users [7%] Vs 3,357 non-users).
Individual factors
In the unadjusted analysis, lower socio-economic status and poor mental health were significant risk factors but were not significant in the adjusted model. Within the adjusted multivariable model, current cannabis users were significantly more likely to report current alcohol use (aOR 2.67, 95% CI: 1.77–4.02), smoking (aOR 3.15, 95% CI: 2.16–4.59) and e-cigarette use (aOR 2.73, 95% CI: 1.87–3.99). Adolescents who did not perceive cannabis use as harmful were also significantly more likely to be current cannabis users compared to those who did (aOR 2.32, 95% CI: 1.65–3.45).
Family-related factors
In the unadjusted analysis, parent knowledge of peers was significant but did not retain significance in the adjusted model. From the multivariable model, adolescents who felt their parents would be ambivalent towards their use of cannabis were significantly more likely to be current cannabis users than those who thought their parents were strongly against cannabis use (aOR 3.69, 95% CI: 2.41–5.66). Low parental supervision was significantly associated with higher odds of current cannabis use (aOR 1.11, 95% CI: 1.01–1.22).
Peer-related factors
Those who reported that their friends used cannabis had a 10-fold increased odds of cannabis use themselves compared to those that did not (aOR 10.17, 95% CI: 5.96–17.35). Participants who felt it was necessary to use cannabis to fit in with their friends had significantly increased odds of current cannabis use compared to those who did not feel peer pressure to use cannabis (aOR 1.85, 95% CI: 1.05–3.26).
School and community related factors
The results from the unadjusted model found significant protective effects for cannabis use but these did not retain significance in the adjusted model.
Key differences between cannabis users and non-users are shown in Figure 1.
Figure 1. Prevalence of risk factors between current cannabis users (n = 302) and non-users (n = 3770) in adolescence.
Discussion
Epidemiology of cannabis use
This study found that among a general population sample of 15–16-year-olds in Ireland, 7.3% had used cannabis in the last 30 days, indicating cannabis use remains an issue among Irish adolescents (Doyle et al., Reference Doyle, Sunday, Galvin and Mongan2022; Sunday et al., Reference Sunday, Keogan, Hanafin and Clancy2020; Költő et al., Reference Költő, Gavin, Molcho, Kelly, Walker and Nic Gabhainn2020).
Individual level risk factors associated with cannabis use
A notable finding in this study was the lack of an association between gender and cannabis use. Historically, male gender has been noted as a risk factor for cannabis use, with more recent evidence suggesting this gap is narrowing (Doyle et al., Reference Doyle, Sunday, Galvin and Mongan2022; Sunday et al., Reference Sunday, Keogan, Hanafin and Clancy2020; Coffey and Patton Reference Coffey and Patton2016; Vidourek et al., Reference Vidourek, King and Montgomery2017; Kuhn Reference Kuhn2015; Matteau-Pelletier et al., Reference Matteau-Pelletier, Bélanger, Leatherdale, Desbiens and Haddad2020). To our knowledge, this is the first study in the Irish setting to find no significant difference in cannabis use between males (50.5%) and females (45.3%).
The odds of cannabis use were higher for current alcohol users, smokers and e-cigarette users, adjusted for all other factors. This finding is in keeping with the literature that risky substance use behaviours co-occur among adolescents (Myers and Kelly Reference Myers and Kelly2006). The fact that adolescents are likely to engage in polysubstance use is significant and needs to be factored into any interventions targeting cannabis prevention among adolescents in Ireland.
We found that 36% of participants in this study were either unsure or felt cannabis use was not harmful. Those who did not perceive cannabis use as harmful had significantly higher odds of cannabis use than those who did perceive it as harmful. This finding is consistent with the international literature on adolescent cannabis use (Mariani and Williams Reference Mariani and Williams2021; Mennis et al., Reference Mennis, McKeon and Stahler2023). Over the last decade, there has been a cultural shift both nationally and internationally towards legalising cannabis use (Willoughby et al., Reference Willoughby, Hust, Li and Couto2023). This cultural shift has led to an attitude among many adolescents and adults that cannabis is a relatively harmless drug (Leung et al., Reference Leung, Chan, Hides and Hall2020; Sunday et al., Reference Sunday, Keogan, Hanafin and Clancy2020). This shift in perception regarding cannabis-related harm may impact Irish adolescents’ decision to use cannabis, as suggested by our findings.
Parental risk factors for adolescent cannabis use
This study has demonstrated the importance of parental attitudes to cannabis use. Adolescents who perceived parental ambivalence towards cannabis use had almost four times the odds of using cannabis. This is a very significant finding as it is a readily modifiable risk factor that may be targeted with prevention initiatives (Vermeulen-Smit et al., Reference Vermeulen-Smit, Verdurmen, Engels and Vollebergh2015). This indicates the critical importance of understanding parental attitudes towards adolescent cannabis use, and the potential modifications needed for drug prevention strategies in order to mitigate against this. In association with the decline in perceived risks of cannabis among teenagers, adults in Ireland as now less inclined to perceive cannabis as harmful (Mongan et al. Reference Mongan, Millar, O’Dwyer, Galvin and Smyth2023). Cannabis use has been legalised in several countries internationally which can influence public opinion about cannabis and reduce knowledge about harms (Cohn et al., Reference Cohn, Alexander, Ehlke, Smith, Lowery, McQuoid and Kendzor2023). There should be clearer public health messaging around the significant health and social harms associated with cannabis use for youth (Rutherford et al., Reference Rutherford, Lim, Johnson, Cheng, Chung, Huang, Sun, Leung, Stjepanović and Chan2023).
In keeping with previous literature, we found that less supervised adolescents had significantly increased odds of cannabis use compared to their more supervised peers. The odds of cannabis use significantly increased with each unit decrease parental supervision scale. Strengthening parental supervision was a key element implemented in Iceland as part of their drug prevention model. Parents in Iceland were invited to school meetings where research findings were shared. Parents then mutually agreed not to allow substance use in their homes, to prevent unsupervised parties, and to increase parental monitoring and the amount of time they spend with their children each week (Kristjánsson et al., Reference Kristjánsson, Mann, Sigfusson, Thorisdottir, Allegrante and Sigfúsdóttir2020). Intervention evaluation showed that parental monitoring increased and substance use decreased in specific communities in Iceland (Kristjánsson et al., Reference Kristjánsson, James, Allegrante, Sigfusdottir and Helgason2010). This suggests that low parental supervision is a modifiable risk factor which Irish drug prevention initiatives may target.
The vast majority of cannabis users reported having friends who also use cannabis (93.5%). The odds of using cannabis were almost ten times higher in those whose friends’ used cannabis compared to adolescents whose friends did not use cannabis. This finding is consistent with the literature, which identifies peer cannabis use as one of the strongest risk factors for adolescent cannabis use (Suárez-Maldonado et al., Reference Suárez-Maldonado, Domínguez-Martínez and Benjet2022; Thomas et al., Reference Thomas, Salvatore, Gillespie, Aliev, Ksinan and Dick2021). Also in keeping with the literature, this study found that the odds of cannabis use were almost double for those who felt peer pressure to use cannabis compared to those who did not (Keyzers et al., Reference Keyzers, Lee and Dworkin2020).
Strengths and limitations
The strengths of this study include its large sample size, high response rate (88.9% of schools and 80.1% of students) and its basis in recently collected data (2021). This study progresses the current understanding of risks and protective factors for cannabis use in adolescence, and in doing so bridges current research gaps as highlighted by previous reviews (Butler et al., Reference Butler, Romano and Leatherdale2022). Reviews have noted issues relating to the exclusion of community and school factors, and lack of insight into interpersonal, individual and gender factors. This paper attempted to overcome these issues exploring such factors, while adopting a robust, fully adjusted statistical analysis. Moreover, this paper underscores that potential protective factors can also act as risk factors if not appropriately managed. For instance, parental supervision, when high, acts as a protective factor, whereas inadequate supervision becomes a risk factor.
There are however limitations to this study, perhaps the most significant being that it is cross-sectional. Causality cannot be established and the temporal direction of relationships between protective and risk factors for cannabis use cannot be proven. Sociodemographic information was not available for those who did not take part in the study, and they may systematically differ from those who did. Previous studies have found non-responders are often more likely to be those who would report risk behaviours, which could lead to underestimation of risk factor prevalence (Cheung et al., Reference Cheung, Ten Klooster, Smit, De Vries and Pieterse2017).
Surveys were completed during school hours and on school premises, which may introduce bias in the reporting of behaviours, particularly cannabis use although this is mitigated by the anonymous nature of the survey. Early school dropouts were not included. However, this limitation is mitigated by including Youth Reach centres in the survey.
This study does not differentiate those who use cannabis infrequently from the heavier daily users who are more at risk of cannabis-related harms. Furthermore, this study does not account for polysubstance use within current cannabis users, as previous research has demonstrated users often engage in polysubstance use (Connor et al., Reference Connor, Gullo, Chan, Young and Hall2013).
Finally, while many of the risk and protective factors identified in this study are consistent with previous international literature, this study is based on adolescents living in Ireland and its generalisability to other contexts may be limited.
Conclusions
This study examined the prevalence of and potential risk and protective factors for cannabis use among 15–16-year-old adolescents in the North East of Ireland.
This study found five risk factors (alcohol use, smoking, e-cigarette use, peer cannabis use and peer pressure to use cannabis) and three protective factors (belief in cannabis-related harm, parental supervision and perception that parents are against cannabis use) independently associated with cannabis use. Importantly, for policymakers, many of these factors are modifiable.
A tailored public health messaging campaign addressing the known harms and complications of cannabis use in young people, is urgently required. Recent conversations around the decriminalisation and legalisation of cannabis and potential use of cannabis for medicinal purposes have contributed to a growing societal acceptance of cannabis use and a perception by some that its use is without risk. The public health community and policymakers must act to ensure greater awareness of cannabis harms among both teenagers and their parents.
Acknowledgements
We wish to thank all young people who participated in the Planet Youth North Dublin, Cavan and Monaghan surveys, as well as the school staff and study administrators that facilitated it. Many thanks also the Planet Youth Implementation Team for North Dublin, Cavan and Monaghan (https://planetyouthpartner.ie), particularly those from the Cavan and Monaghan Education and Training Board (Maureen McIntyre, Collette Deeney), the North Dublin Regional Drug and Alcohol Task Force (Bríd Walsh, David Creed), the North Eastern Regional Drug & Alcohol Task Force (Andy Ogle), and TUSLA (Ste Corrigan).
Author contributions
Conceptualisation, T.M.O., M.C, B.S, E.P.; Analysis, T.M.O.; Data Interpretation, T.M.O, R.F, N.D, L.Q, M.C, B.S; Methodology, T.M.O., M.C, B.S, E.P., L.Q.; Project administration, M.C.; Writing—original draft, T.M.O; Manuscript writing, reviewing, R.F, N.D, B.S, M.C, T.M.O. All authors have read and agreed to the published version of the manuscript. T.M.O. and R.F are joint first authors.
Financial support
This research was supported by the Health Research Board (ILP-PHR-2019-009 and CDA-2018-001). This publication has also emanated from research supported in part by research grants from the Health Research Board (CDA 2021-005; ILP-POR-2017-039; ILP POR 2019-0005) and a research grant from Research Ireland under Grant number 21/RC/10294_P2 and by an RCSI Summer studentship to SP.
Competing interests
None.
Ethical standards
Ethical approval was granted by the Royal College of Physicians of Ireland.
The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional committee on human experimentation and with the Helsinki Declaration of 1975, as revised in 2008. The authors assert that ethical approval for publication of this study has been provided by their local Ethics Committee (RCPI RECSAF 144).
