NEET categorization identifies youth who are disconnected from employment and education structures, i.e., not engaged in any form of employment, education, or training structures . Precarious/institutional housing status included any participants who indicated living in a rooming or boarding house, group home, foster care, supportive/transitional housing, treatment facility, or shelter, or who were couch surfing or living on the street . The items in the GAIN-SS are endorsed based on recency of symptoms, i.e. 0 , 1 , 2 and 3 . For the purposes of the current analyses, past month and 2–12 months were combined to indicate past year symptom endorsement. Each scale score is based on the number of symptoms endorsed in the past year, with scores ranging from 0 to 5. Based on scale standards, a youth is considered to have a high probability for a diagnosis if three or more items in a subscale are endorsed in the past year. In the current study, the GAIN-SS domains were analyzed as continuous scores rather than cutoff scores for the likelihood of a diagnosis due to a ceiling effect. With permission from Chestnut Health Systems to the project leads at [BLIND], the GAIN-SS was modified by adding seven items to create a 27 item version that was used in this project. The seven additional items screen for traumatic stress , distorted thinking , excessive internet or videogame use , gambling issues and eating concerns .The Trauma History Screen was used . It asks respondents to endorse whether they have ever experienced any of 13 specific forms of traumatic events, including accidents, natural disasters, sexual trauma, bullying, etc., plus one item referring to any “other” type of traumatic event. The test-retest reliability of the exposure to the assessed stressors has been found to be .93 for the total scale score . To tailor the tool to an adolescent sample, our team removed an item referring to military trauma and added two items referring to experiencing bullying ; other minor adjustments were made to adapt to a youth population . The resulting scale had 14 specific items and one ‘other’ item. For the purposes of this study, the trauma variable is defined as the sum of the number of types of trauma to which the participant has been exposed ; analyses were rerun excluding the bullying items given that they are newly added, unvalidated items.
The exposure variable of interest in the current analyses is the age of first use of cannabis, dichotomized as < 14 years of age versus 14+, followed by age of onset as a continuous variable in the final analyses. Using descriptive statistics, we characterized the sample on demographic characteristics using chi-square analyses. We conducted the subsequent analyses controlling for sex and duration of use, given that there were duration of use differences between the two groups in association with age and that sex differences are consistently found in cannabis use behaviours . We then conducted multiple logistic regression analyses, vertical grow system controlling for sex and duration of use, independently for individual exposure variables, which included each substance use variable . Crosstabulations described proportions by age group. We conducted ANCOVAs to analyze the association between cannabis age of onset groups and GAIN-SS domains, controlling for duration of use and sex, with logistic regressions for the GAIN-SS extension items. We then identified the substances that participants reported most often as the substance first used based on the AADIS-age of onset variable; since almost all participants reported their youngest age of onset for cannabis, tobacco, and/or alcohol, these three substances were further explored. Venn diagrams were drawn using EulerAPE software to characterize the age of the first substance of use in the 14+ and < 14 groups, examining age-of-first use percentages for each substance and then age-of-first use percentages for co-occurring substances when there was overlap, with chi-square tests for significance. Based on the exploratory findings and to expand on the findings for the two dichotomous age groupings, we conducted multiple regression analyses to identify factors uniquely associated with age of first cannabis use as a continuous variable; entered into the model were sex and duration of use in Block 1 as control variables, then in Block 2, each of the primary variables identified as significant in the between-group comparisons . Collinearity diagnoses demonstrated that none of the variables were highly correlated. Pairwise deletion was used. For multiple comparisons, the False Discovery Rate correction was used . Statistical analyses were conducted with using SPSS 24.0 . This study characterized clinical risk profiles for those initiating cannabis use in early adolescence , i.e., prior to the transition to secondary school and in an age range rarely considered in research, in comparison to those initiating cannabis use in mid-to-late adolescence through to early adulthood , through direct comparison of patterns of substance use behaviours and co-occurring concerns. Nearly 30% of service-seeking youth reported initiating cannabis use before the age of 14. Results support distinct and clinically meaningful differences between these age groups, with earlier cannabis use initiation serving as an important marker for more problematic concurrent mental health and substance use concerns.
The under 14 and 14+ groups had similar sociodemographic profiles, with some important differences: the under 14 group was more likely to be NEET, precariously housed, and involved in the legal system. The under 14 group also reported more frequent polysubstance use, with an earlier age of onset for all substances. Youth initiating cannabis use at under age 14 endorsed more externalizing disorder symptoms, more crime/violence-related behaviors, and more co-occurring concerns. This finding did not hold up in the current study; however, internalizing disorder symptoms were high across both early and later onset cannabis users in the current study, suggesting a ceiling effect. The association between early cannabis use and externalizing disorders found in the current study has been previously demonstrated . Co-occurring challenges were highly endorsed: those in the under 14 group in the current sample were more likely to endorse symptoms from all four domains of the GAIN-SS . Higher trauma exposure is an additional notable finding, given the demonstrated association between trauma, mental health challenges, and self-medication via substance use . Further research is required to better understand the role of a diversity of risk factors — including mental health, concurrent disorders, trauma, environmental and social risk factors — and how they may influence each other leading to varying levels of risk for early age of cannabis use onset. In terms of polysubstance use profiles, participants who began using cannabis under the age of 14 were more likely to begin their substance use trajectories with cannabis rather than alcohol, which differed from the profiles of those who initiated cannabis at a later age; early cannabis initiators also initiated other substances at a younger age. Behrendt et al. found that alcohol use preceded cannabis use for a vast majority of young people and that only 4.4% reported initiating cannabis and alcohol use in the same year; given changes in the social acceptability of cannabis, the increased rate of cannabis as a first substance of use and of concurrent onset of cannabis and alcohol may be a cohort effect that requires further attention in research. Previous literature has supported an association between early cannabis initiation and the development of CUD . However, little guiding research is available to shed light on the trajectories of the earliest cannabis initiators. Previous research has pointed to the role of polysubstance use in ongoing substance use trajectories ), a finding that was supported in the current study. There are a number of possible risk and protective factors that may potentially mediate and moderate progression to CUDs, such as resilience, substance use among peers, polysubstance use, legal system involvement, and mental health service. An important future research direction will be to investigate the role of diverse risk factors and protective factors in the progression towards and away from CUD. A secondary and more exploratory goal of the current study was to identify which of the sociodemographic, substance use and mental health variables would hold as unique associations with earlier onset cannabis use. Legal system involvement and crime/ violence behaviors were most strongly associated with early cannabis initiation. The relation between early cannabis use onset and factors such as crime/violence and externalizing disorders have previously been demonstrated . Youth with legal system involvement are often found to have social networks that consist of peers with behavioral issues and substance use , and are often characterized as having risk associated with particular personality profiles.
Legal system involvement may reflect social and/or personality risk factors that may be more predictive of early initiation of cannabis grow equipment. Combined with the higher externalizing disorder symptoms, criminal justice involvement may point to behavioral concerns that may lead to both early cannabis use and crime and violence challenges, although the directionality is unclear. However, it should be noted that most of the data was collected while cannabis use was illegal in Canada for people of all ages locally; further work should explore how these findings might change with changes in legislation. Nevertheless, previous research has suggested that youth with cannabis use who are referred by the criminal justice system may stay in treatment longer than those who were not referred , and that they can benefit substantially from substance use treatment . Additional supports for navigating the criminal justice system may be warranted for some youth in this group. These findings have important implications for cannabis-use prevention, early intervention, and treatment initiatives. Findings are mixed on whether prevention initiatives are effective in younger or older adolescents. A meta-analysis of cannabis prevention interventions for adolescents found interventions are more effective among high school students than among younger students, a finding that was attributed to developmental factors . However, another systematic review found programs designed to prevent cannabis use among adolescents and young adults to be more effective when targeted towards a younger age group , since the program would potentially precede the onset of cannabis use . Based on the findings of the current study, interventions aiming to prevent or delay the first use of cannabis should start early, particularly for more vulnerable children and youth. Targeting older students may be too late for some youth. Optimal prevention and early intervention efforts should be developed with the knowledge that some youth will have already tried cannabis, even during childhood; as these may be the most vulnerable youth, it should be kept in mind that they may also have considerably more concurrent issues. Preventionists and early interventionists are encouraged to continue working to optimize cannabis prevention programs in age-appropriate ways for children and youth at different ages and with different levels of cannabis experience or non-experience. Overall, these findings have meaningful clinical implications for treatment among youth seeking services across sectors. Notably, the results highlight the importance of taking early cannabis initiation into account to understand the vulnerabilities and concurrent mental health, behavioral, substance use, and other concerns of youth. However, as about half of youth among both early cannabis initiators and later initiators began using cannabis, alcohol, and tobacco at about the same time, the use of any of these substances should be taken into account as markers that may suggest the need for further assessment of substance use. Given the comorbidity of mental health and substance use problems in youth, especially youth with higher levels of vulnerability, like those who initiate cannabis use early, youth-focused service providers are encouraged to consider youth substance use as part of routine youth mental health and wellness services. For youth presenting with substance-related problems, service providers should consider current and previous substance use, particularly age of cannabis use onset, as part of the assessment and service planning process. For treatment services, asking the age of onset of cannabis use may provide insight into historical and current vulnerabilities, as the duration of use is strongly associated with multiple outcomes.