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. 2022 Oct 1;5:100101. doi: 10.1016/j.dadr.2022.100101

Risky cannabis use is associated with varying modes of cannabis consumption: Gender differences among Canadian high school students

Isabella Romano a,⁎, Alexandra Butler a, Gillian Williams a, Sarah Aleyan b, Karen A Patte c, Scott T Leatherdale a
PMCID: PMC9948853  PMID: 36844170

Highlights

  • •

    38% of youth who used cannabis in the past year used multiple modes.

  • •

    Over one third of youth who used cannabis in the past year engaged in solitary use.

  • •

    Males and females who used cannabis alone were more likely to use multiple modes.

  • •

    For females, using cannabis alone was associated with exclusive use of edibles.

  • •

    Early age use was negatively associated with vaping for males, edibles for females.

Keywords: Cannabis use, Marijuana use, Adolescent behavior, Substance use

Abstract

Background

Our objective was to explore associations between indicators of more risky cannabis use (i.e., solitary use, frequent use, and younger age of initiation) and different modes of cannabis use (i.e., smoking, vaping and/or edibles).

Methods

Data were gathered from a large sample of Canadian youth in Alberta, British Columbia, Ontario, and Quebec who participated in Year 8 (2019–20) of the COMPASS study, and who reported using cannabis in the past year (n = 4,763). Generalized estimating equations were used to examine associations between risky cannabis use and modes of cannabis use, stratified by gender.

Results

Overall, 38% of students reported using multiple modes of cannabis use. Consistent among both males and females, students who used cannabis alone (35%) and at a higher frequency (55%) were more likely to use multiple modes than smoking only. Among females, those who used cannabis alone were more likely to report using edibles only compared to smoking only (aOR=2.27, 95%CI=1.29–3.98). Earlier cannabis use initiation was associated with lower likelihood of vaping cannabis only among males (aOR=0.25; 95%CI = 0.12–0.51), and lower likelihood of using edibles only among females (aOR=0.35; 95%CI = 0.13–0.95), than by smoking only.

Conclusions

Our findings suggest that multiple modes of use may be an important indicator or risky cannabis use among youth, given associations with frequency, solitary use, and age of onset.

1. Introduction

Certain cannabis use behaviors are associated with greater risk for cannabis-related problems such as dependency and other negative psychosocial and behavioral outcomes. Risky cannabis use is typically categorized by greater frequency and volume of use, younger age of initiation (Dragt et al., 2010), increased product potency (Freeman and Winstock, 2015; Health Canada, 2016; Stuyt, 2018), as well as the context within which cannabis is used (e.g., social use vs. solitary use) (Noack et al., 2011; Tucker et al., 2006; Van der Pol et al., 2013). In general, research suggests that the younger and more frequently cannabis is used, the greater the risk for cannabis-related harms (Gorey et al., 2019; Health Canada, 2016). Additionally, high potency cannabis products are associated with increased risk of cannabis use disorder, greater severity of dependence, and adverse health events (e.g., hospitalization due to toxicity, episodes of psychosis), particularly among young people (Freeman and Winstock, 2015). Solitary cannabis use, or using cannabis alone, has been linked with more frequent cannabis use, poorer mental health and academic outcomes (Noack et al., 2011; Tucker et al., 2006; Van der Pol et al., 2013), and problematic substance use in both adolescence (Creswell et al., 2015) and adulthood (Tucker et al., 2006).

As Canada's legal cannabis market continues to grow, a number of new cannabis products have become available as alternatives to traditional combustion methods. Notably, cannabis use has only been legalized for adult use in Canada, and remains federally illegal for youth under 18 years (with some provincial exceptions, e.g., 19 in Ontario, 21 in Quebec). Health Canada recognizes four main modes of cannabis consumption legalized for adult use: smoking (i.e., involving combustion via joints, pipes, bongs, etc.), ingesting (i.e., eating, drinking), vaporizing (i.e., using a vaporizer or vaping device), and dabbing (akin to vaporizing, but whereby cannabis concentrates are heated on a hot surface). The 2020 Canadian Cannabis Survey results indicate that among those who used cannabis, 79% reported smoking it, 52% reported using edibles, 24% reported using via a vape pen, and 12% reported consumption via a vaporizer (Government of Canada, 2020). Although smoking remains the most common mode of cannabis use, there has been an observed shift in modes of cannabis use and the prevalence of consuming cannabis via non-combustible modes (i.e., edibles, vaping) is increasing within Canada and the U.S. (Budney et al., 2015; Government of Canada, 2020; Krauss et al., 2017; Schauer et al., 2016).

Mode of use has recently been described as another important cannabis use indicator (Gunn et al., 2020). In fact, multiple cannabis product use among youth may represent a unique risk factor associated with other risky behaviors including driving under the influence of cannabis (Krauss et al., 2017) and other substance use (Fedorova et al., 2019). Non-combustible cannabis products are often perceived as lower risk compared to the traditional mode of cannabis use by smoking (Borodovsky et al., 2016; Johnson et al., 2016) and are easier to consume discretely (Yingst et al., 2019). However, non-combustible cannabis products are typically more potent with respect to THC concentration (Hammond, 2019), posing additional implications for risk of over-ingestion. In terms of adverse respiratory effects, modes of cannabis use which do not involve combustion may be more closely aligned with harm reduction approaches (Shiplo et al., 2016). Regardless, recent evidence suggests that youth are more likely to supplement smoking cannabis with other non-combustible products rather than replace smoking (Doggett et al., 2021). Positive perceptions of non-combustible cannabis products may incentivize use by youth, prompting an increased likelihood of experimenting with, and more frequent use of cannabis, earlier age of initiation, and positive initial experiences (Wills et al., 2015) – potentially leading to future problematic use and disorders (Budney et al., 2015). In addition to these concerns, the potency of non-combustible cannabis products is highly variable; while legal edible cannabis products are regulated for adult use in Canada, illicit products remain available and do not necessarily follow preparation or packaging guidelines. As such, there is a risk of inadvertent over-ingestion of cannabis, especially for edibles that have a delayed onset of intoxication (Lemberger et al., 1972), all of which can result in adverse and unwanted effects, toxicity, and hospitalization (Borodovsky et al., 2016; Cao et al., 2016; Kim et al., 2016). On the other hand, modes of cannabis use which do not involve smoking are aligned with harm reduction approaches to adverse respiratory effects.

Risky cannabis use behaviors may vary by gender; for instance, males represented 81.2% of cases of cannabis-related deaths in Australia over the period 2000–2018 (Zahra et al., 2020). Additionally, some research has observed earlier initiation of cannabis (Bryan et al., 2012), more frequent use of cannabis (Cuttler et al., 2016; Foster et al., 2016; Legleye et al., 2014), and higher rates of solitary cannabis use to be more common among male adolescents compared to their female counterparts (Creswell et al., 2015; Noack et al., 2011). However, this evidence remains mixed (Tucker et al., 2014). Previous research has also identified differences between modes of cannabis use between male and females; alternative modes of cannabis (e.g., eating, drinking, vaping) may be used more frequently by females (Doggett et al., 2021; Friese et al., 2016), though recent longitudinal research suggests that transitions between, or additions of other modes of cannabis use, vary over time and among males and females (Doggett et al., 2021). Further research is required to delineate the gender-based differences of risky cannabis use behaviors and modes of use among adolescents to help tailor more effective prevention programs.

Few studies have identified the characteristics of youth and patterns of use by mode of cannabis consumption. A greater understanding of how various modes of cannabis use differ by risky cannabis use behaviors is essential for the development of evidence-driven policies that will help minimize potential health risks within this demographic. Among a sample of Canadian youth who report using cannabis, we sought to explore associations between engagement in risky cannabis use (i.e., solitary use, frequent use, and younger age of initiation) and different modes of cannabis use (i.e., smoking, vaping and/or edibles). Specifically, our objectives were to: 1) estimate the rate of risky cannabis use and different modes of use behaviors in our sample, 2) examine how indicators of risky cannabis use are differentially associated with varying modes of cannabis consumption, and 3) to investigate how these associations may differ by gender among youth in Canada.

2. Methods

2.1. Study design

The COMPASS study was designed to collect prospective data on youth health annually from a large convenience sample of Canadian secondary schools and the students attending those schools. The current study reports on cross-sectional, student-level survey data collected during class-time among schools in Alberta, British Columbia, Ontario, and Quebec during Year 8 (Y8 [2019–20]) of COMPASS, prior to school closures related to the COVID-19 pandemic response. Data were collected between September 2019 and February 2020. Active-information, passive-consent protocols were employed to promote student enrollment and encourage response validity (Thompson-Haile et al., 2013). Additional details relating to COMPASS Study methods and procedures are available in print (Leatherdale et al., 2014) and online (www.COMPASS.UWaterloo.ca). All procedures including the use of passive-consent procedures received approval from the Office of Research Ethics (ORE #30,118) at the University of Waterloo and from participating school boards.

2.2. Study sample

Data were collected from 29,770 secondary school students in grades 9 to 12 (Secondary I-V in Quebec, grade 7 to 11 equivalent) attending 51 schools (6 in Alberta, 9 in British Columbia, 18 in Ontario, 18 in Quebec). Students’ ages range from 12 to 19. For the current study, we restricted participants to those who reported having used cannabis in the past 12 months (n = 6539, 22.0% of full sample) and those who indicated their gender as female or male (n = 6093). After cases with missing data were also removed (n = 1330, 21.8%), our final analytic sample consisted of 4763 students (50.2% male, 49.8% female).

We conducted separate analyses to examine the characteristics of students who were missing data related to mode of cannabis use (Supplementary File A). Overall, 1081 students (16.5%) did not report a mode of cannabis use. Students who identified as BIPOC (Black, Indigenous, and/or Person of Color) were slightly more likely to have missing mode of use data (OR=1.23, 95% CI [1.05, 1.44]), as were students outside of Ontario (ORAB=1.37, 95% CI [1.09, 1.72]; ORBC=1.37, 95% CI [1.14, 1.64]; ORQC=1.52, 95% CI [1.27, 1.82]).

2.3. Measures

2.3.1. Dependent variable of interest – mode of cannabis use

Students who reported using cannabis in the past 12 months were asked the following question: “If you have used marijuana or cannabis in the last 12 months, how did you use it?” and told to select all that apply from the following options: “I have used [cannabis] by smoking it (e.g., in a joint, a pipe, a bong),” “I have used [cannabis] by vaping it,” and “I have used [cannabis] by eating or drinking it (e.g., in brownies, cookies, candies, tea).” Based on student responses, mode of cannabis use (0 = smoking only [ref.], 1 = vaping only, 2 = edibles only, 3 = multiple modes) was employed as our outcome variable of interest.

2.3.2. Independent variables of interest – risky cannabis use behaviors

Solitary cannabis use. Students were asked to indicate how often they “used marijuana or cannabis when you were all by yourself” during the past 30 days, with the response options: “never,” “once,” “twice,” or “3 or more times.” Students who reported using cannabis by themselves at least once in the past 30 days were labelled yes to solitary cannabis use, and those who did not report engaging in the behavior were labelled no [ref.].

Frequency of cannabis use. Students who used cannabis were also asked to report the frequency at which they did so in the past 12 months, using the question: “…how often did you use marijuana or cannabis?” Response options included: “every day,” “4–6 times a week,” “2 or 3 times a week,” “once a week,” “2 or 3 times a month,” “once a month,” “less than once a month,” “I have used marijuana but not in the last 12 months,” “I have never used marijuana.” We dichotomized students according to whether or not they reported using cannabis less than once per month [ref.] or at least once per month; higher frequency of use could not be explored due to too small of cell counts when considering different modes of use in the models. Frequency of cannabis use reflected frequency of any mode of cannabis use in the past year; frequency for each mode of use was not reported.

Age of cannabis use initiation. The same students were asked to disclose how old they were when they first tried cannabis. Age of initiation was grouped into three categories (< 14 years, 14–16 years, ≥ 16 years [ref.]).

2.3.3. Sociodemographic covariates

Students were asked “Are you male or female?” and were given the following response options: “female,” “male,” “I describe my gender in a different way,” and “I prefer not to say.” While this variable was intended to refer to gender, we continue to use the terms “female” and “male” henceforth as those were the response categories used in the COMPASS Y8 student questionnaire. For the purpose of the current study, we used data from students who indicated their gender as female or male [ref.], as the subgroup of students who indicated otherwise was too small (n = 262) for stratified analyses (see Supplementary File B for descriptive statistics among non-binary/gender diverse participants). Students also reported their age (in years) and ethnicity or race, which we categorized as BIPOC (Asian, Black, Indigenous, Latin American/Hispanic, other, multiple ethnicity/race) or white ([ref.]). As a proxy to socioeconomic status and indicator of part-time employment, students were also asked to report the amount of spending money they have access to weekly (zero [ref.], $1–20, $21–100, >$100, don't know). Use of weekly spending money is consistent with previous youth behavioral health literature (Currie et al., 1997; Elton-Marshall et al., 2011), and is shown to be associated with youth substance use (Czoli et al., 2015; Markowitz and Tauras, 2006; Romano et al., 2019; Zuckermann et al., 2020).

2.4. Analyses

Using descriptive statistics (χ2), we examined the characteristics of students who reported past-year cannabis use by gender and by mode of use. We then fit a gender-stratified model using generalized estimating equations (GEE) to examine how risky cannabis use behaviors (solitary use, frequency of use, age of initiation) were associated with mode of cannabis use among students who reported using cannabis in the past 12 months, while testing for the effects of relevant sociodemographic covariates (age, ethnicity/race, weekly spending money) and adjusting for province. A single model was run with all variables included. To account for the multinomial distribution of our dependent variable of interest, we specified a generalized logit link function that treated the ‘smoking only’ response category as the referent against which the ‘vaping only,’ ‘edibles only,’ and ‘multiple modes’ response categories were compared. We exponentiated the estimates from the GEE model to obtain adjusted odds ratios and reported them alongside 95% confidence intervals. We accounted for the clustered structure of the data (i.e., students clustered within schools) by specifying a repeated subject statement in PROC GEE using an independent covariance structure. We used SAS version 9.4 software (SAS Institute, 2016).

3. Results

3.1. Sample characteristics

In our sample of 4763 secondary school students who reported using cannabis in the past 12 months, approximately half (50%, n = 2370) were female. The mean student age was 15.7 years (SD: 1.1, range: 12–19) and 71% identified as white.

Most students (54%, n = 2573) reported using cannabis by smoking only. Fewer than 5% reported either vaping (3%, n = 161) or eating (4%, n = 191) cannabis only, and 38% (n = 1838) reported using multiple modes in the past 12 months. Overall, 35% of students (n = 1648) had engaged in solitary cannabis use at least once during the past 30 days. More than half (55%) of students in our sample used cannabis at a frequency of at least once per month, and the majority (53%) were between 14 and 16 years when they tried cannabis for the first time.

Differences by gender in mode of use and cannabis use behaviors are shown in Table 1. Mode of use did not differ by gender, although significant differences were found among males and females in solitary cannabis use (χ2=32.8, p<0.0001), frequency of use (χ2=41.9, p<0.0001), and age of initiation (χ2=7.2, p<0.0001). Descriptive comparisons for mode of use by students’ characteristics are also presented in Table 2. Mode of use significantly differed by solitary use status (χ2=237.1, p<0.0001), frequency of cannabis use (χ2=348.9, p<0.0001), and age of cannabis use initiation (χ2=55.4, p<0.0001).

Table 1.

Characteristics of 4763 high school students who reported past-year cannabis use in COMPASS 2019–20.

Full sample Gender, n (%)
 χ2, t (df) p
Measure Male Female
Mode of cannabis use
Smoking only (ref.) 2573 (54.0) 1326 (55.4) 1247 (52.6) 6.5 (3) 0.0878
Vaping only 161 (3.4) 85 (3.6) 76 (3.2)
Edibles only 191 (4.0) 84 (3.5) 107 (4.5)
Multiple modes 1838 (38.6) 898 (37.5) 940 (39.7)
Smoke, vape, eat 891 (16.3) 436 (16.86) 344 (13.83)
Smoke, vape 470 (8.61) 234 (9.05) 213 (8.56)
Smoke, eat 742 (13.59) 284 (10.98) 405 (16.28)
Vape, eat 27 (0.49) 8 (0.31) 18 (0.72)
Solitary cannabis use
No (ref.) 3115 (65.4) 1471 (61.5) 1644 (69.4) 32.8 (1) <0.0001
Yes 1648 (34.6) 922 (38.5) 726 (30.6)
Frequency of cannabis use
< 1/month (ref.) 2144 (45.0) 966 (40.4) 1178 (49.7) 41.9 (1) <0.0001
≥ 1/month 2619 (55.0) 1427 (59.6) 1192 (50.3)
Age of cannabis use initiation
≥ 16 years (ref.) 1098 (22.9) 539 (22.5) 550 (23.2) 7.2 (2) 0.0278
14–16 years 2532 (53.2) 1241 (51.9) 1291 (54.5)
< 14 years 1142 (23.9) 613 (25.6) 529 (22.3)
Age, years
Mean, SD 15.7 (1.2) 15.8 (1.2) 15.7 (1.1) 3.2 (4761) 0.0016
Ethnicity/race
White (ref.) 3395 (71.3) 1662 (69.5) 1733 (73.1) 7.8 (1) 0.0051
BIPOC 1368 (28.7) 731 (30.5) 637 (26.9)
Weekly spending money
Zero (ref.) 451 (9.5) 236 (9.9) 215 (9.1) 17.7 (4) 0.0014
$1-$20 831 (17.5) 378 (15.8) 453 (19.1)
$21-$100 1359 (28.5) 661 (27.6) 698 (29.4)
> $100 1563 (32.8) 841 (35.1) 722 (30.5)
Don't know 559 (11.7) 277 (11.6) 282 (11.9)
Total 4763 (100.0) 2393 (50.2) 2370 (49.8)
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Table 2.

Descriptive comparisons of students’ characteristics by mode of cannabis use among students who reported past-year cannabis use in COMPASS 2019–20 (N = 4763).

n (%)
 χ2, F (df) p
Measure Smoking only Vaping only Edibles only Multiple modes
Solitary cannabis use
No (ref.) 1890 (73.5) 130 (80.7) 137 (71.7) 958 (52.1) 237.1 (3) <0.0001
Yes 683 (26.5) 31 (19.3) 54 (28.3) 880 (47.9)
Frequency of cannabis use
< 1/month (ref.) 1370 (53.3) 113 (70.2) 131 (68.6) 530 (28.8) 348.9 (3) <0.0001
≥ 1/month 1203 (46.7) 48 (29.8) 60 (31.4) 1308 (71.2)
Age of cannabis use initiation
≥ 16 years (ref.) 598 (23.2) 54 (33.5) 72 (37.7) 365 (19.9) 55.4 (6) <0.0001
14–16 years 1384 (53.8) 78 (48.5) 94 (49.2) 976 (53.1)
< 14 years 591 (23.0) 29 (18.0) 25 (13.1) 497 (27.0)
Gender
Male (ref.) 1326 (51.5) 85 (52.8) 84 (44.0) 898 (48.9) 6.5 (3) 0.0878
Female 1247 (48.5) 76 (47.2) 107 (56.0) 940 (51.1)
Age, years
Mean, SD 15.6 (1.1) 15.4 (1.3) 15.9 (1.1) 15.9 (1.1) 19.8 (3) <0.0001
Ethnicity/race
White (ref.) 1913 (74.4) 102 (63.4) 132 (69.1) 1248 (67.9) 27.5 (3) <0.0001
BIPOC 660 (25.6) 59 (36.6) 59 (30.9) 590 (32.1)
Weekly spending money
Zero (ref.) 248 (9.6) 16 (9.9) 16 (8.4) 171 (9.3) 19.7 (12) 0.0723
$1-$20 452 (17.6) 27 (16.8) 28 (14.7) 324 (17.6)
$21-$100 772 (30.0) 45 (28.0) 48 (25.1) 494 (26.9)
> $100 789 (30.7) 49 (30.4) 72 (37.7) 653 (35.5)
Don't know 312 (12.1) 24 (14.9) 27 (14.1) 196 (10.6)
Total 2573 (54.0) 161 (3.4) 191 (4.0) 1838 (38.6)
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Note. Ref. = reference category. SD = standard deviation. Bold values indicate significance at α < 0.05.

3.2. Gender-stratified associations between risky cannabis use behaviors and mode of use

Stratification of GEE models by gender was decided a priori. Tables 3a and 3b present the results of our GEE models for male and female students, respectively. Models estimate the likelihood of students reporting cannabis use via different modes (i.e., vaping only, edibles only, multiple modes) compared to smoking only.

Table 3a.

Generalized estimating equation results predicting mode of past-year cannabis consumption among male students in COMPASS 2019–20 (N = 2393).

aOR (95% CI)
Measure Vaping only Edibles only Multiple modes
Solitary cannabis use
No (ref.) 1.00 1.00 1.00
Yes 1.70 (0.83, 3.47) 1.49 (0.87, 2.55) 1.49*** (1.22, 1.83)
Frequency of cannabis use
< 1/month (ref.) 1.00 1.00 1.00
≥ 1/month 0.33*** (0.18, 0.59) 0.49* (0.27, 0.90) 2.54*** (2.05, 3.16)
Age of cannabis use initiation
≥ 16 years (ref.) 1.00 1.00 1.00
14–16 years 0.31*** (0.19, 0.52) 0.93 (0.46, 1.88) 1.42** (1.12, 1.80)
< 14 years 0.25*** (0.12, 0.51) 0.66 (0.29, 1.48) 1.33 (0.99, 1.78)
Age, years 0.66** (0.51, 0.85) 0.91 (0.72, 1.15) 1.05 (0.96, 1.15)
Ethnicity/race
White (ref.) 1.00 1.00 1.00
BIPOC 1.51 (0.91, 2.50) 1.16 (0.62, 2.16) 0.95 (0.78, 1.15)
Weekly spending money
Zero (ref.) 1.00 1.00 1.00
$1-$20 1.43 (0.63, 3.26) 0.88 (0.35, 2.23) 1.19 (0.81, 1.75)
$21-$100 0.95 (0.38, 2.40) 0.86 (0.41, 1.82) 1.32 (0.98, 1.78)
> $100 1.98 (0.80, 4.86) 1.84 (0.96, 3.53) 1.90*** (1.45, 2.50)
Don't know 0.88 (0.36, 2.17) 0.33 (0.54, 3.25) 1.35 (0.97, 1.89)
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Note. This model predicts the likelihood of students reporting cannabis consumption via ‘vaping only,’ ‘edibles only,’ or ‘multiple modes’ each compared to the reference category, ‘smoking only’ while adjusting for province. ref. = reference category. aOR = adjusted odds ratio. CI = confidence interval. *p<0.05, **p<0.01, ***p<0.001.

Table 3b.

Generalized estimating equation results predicting mode of past-year cannabis consumption among female students in COMPASS 2019–20 (N = 2370).

aOR (95% CI)
Measure Vaping only Edibles only Multiple modes
Solitary cannabis use
No (ref.) 1.00 1.00 1.00
Yes 0.52 (0.26, 1.04) 2.27** (1.29, 3.98) 1.62*** (1.34, 1.95)
Frequency of cannabis use
< 1/month (ref.) 1.00 1.00 1.00
≥ 1/month 0.82 (0.52, 1.28) 0.34*** (0.21, 0.54) 1.79*** (1.46, 2.18)
Age of cannabis use initiation
≥ 16 years (ref.) 1.00 1.00 1.00
14–16 years 0.57 (0.30, 1.08) 0.49** (0.28, 0.84) 1.15 (0.93, 1.42)
< 14 years 0.44 (0.18, 1.08) 0.35* (0.13, 0.95) 1.37* (1.07, 1.77)
Age, years 0.60*** (0.45, 0.79) 0.99 (0.73, 1.34) 1.21*** (1.11, 1.32)
Ethnicity/race
White (ref.) 1.00 1.00 1.00
BIPOC 1.18 (0.66, 2.13) 0.93 (0.51, 1.69) 0.88 (0.69, 1.12)
Weekly spending money
Zero (ref.) 1.00 1.00 1.00
$1-$20 0.57 (0.23, 1.41) 1.26 (0.53, 2.99) 1.11 (0.82, 1.50)
$21-$100 1.19 (0.41, 3.46) 1.47 (0.70, 3.08) 1.03 (0.76, 1.41)
> $100 0.94 (0.30, 2.91) 1.81 (0.86, 3.80) 1.21 (0.86, 1.69)
Don't know 1.68 (0.58, 4.88) 1.97 (0.83, 4.67) 1.09 (0.78, 1.51)
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Note. This model predicts the likelihood of students reporting cannabis consumption via ‘vaping only,’ ‘edibles only,’ or ‘multiple modes’ each compared to the reference category, ‘smoking only’ while adjusting for province. Ref. = reference category. aOR = adjusted odds ratio. CI = confidence interval. *p<0.05, **p<0.01, ***p<0.001.

Male students who reported solitary cannabis use were one and a half times more likely to have used multiple modes of cannabis compared to smoking only (aOR=1.49, p<0.0001; see Table 3a). Those who used cannabis more frequently (≥ 1/month) had higher odds of using multiple modes (aOR=2.54, p<0.0001) but lower odds of using cannabis either by vaping only (aOR=0.33, p<0.001) or using edibles only (aOR=0.49, p<0.05). Compared to males who initiated cannabis use at 16 years or older, cannabis use initiation between 14 and 16 years was associated with higher odds of use by multiple modes (aOR=1.42, p<0.01). Cannabis use initiation at younger ages was associated with lower odds of vaping only (aOR14–16yrs=0.31, p<0.0001; aOR<14yrs=0.25, p<0.001) for males.

As shown in Table 3b, female students who engaged in solitary cannabis use were 1.62 times more likely to report using multiple modes (p<0.0001) and more than twice as likely to have used edibles only (aOR=2.27, p<0.01), compared to smoking only. Female students who used cannabis at least once per month were almost twice as likely to report use of multiple modes (aOR=1.79, p<0.0001) but less likely to use edibles only (aOR=0.34, p<0.0001), compared to smoking only. Age of cannabis use initiation was also associated with mode of use among females; students who first tried cannabis at 14–16 years were less likely to use edibles only than those who initiated use at 16 years or older (aOR=0.49, p<0.01), as were those who tried cannabis for the first time before 14 years (aOR=0.35, p<0.05). Younger cannabis use initiation (< 14 years) among females was associated with higher odds of reporting using multiple modes (aOR=1.38, p<0.05).

Student age was significantly associated with cannabis use mode for both males and females. Specifically, every unit increase in age (years) was associated with a 30–40% lower likelihood that students used cannabis by vaping only, compared to smoking only (aORMales=0.66, p<0.01 [Table 3a]; aORFemales=0.60, p<0.001 [Table 3b]). Among male students, those reporting weekly available spending money over $100 per week were nearly twice as likely as those with no weekly spending money to use cannabis by multiple modes (aOR=1.90, p<0.0001 [Table 3a]). In contrast, weekly spending money was not associated with cannabis use mode among females.

Supplementary File C presents additional results of a single model for the entire sample, testing gender interactions to formally evaluate any significant differences among males and females. Females who engaged in solitary cannabis use were less likely to use cannabis by vaping only (aOR=0.33, p<0.05), but were more likely to vape only if cannabis was used more frequently (aOR=2.17, p<0.05) or initiated between 14 and 16 years (aOR=1.97, p<0.05). Females who used cannabis at least once per month were also less likely to report using multiple modes (aOR=0.70, p<0.01) than smoking only.

4. Discussion

Using self-reported data collected from a large sample of Canadian secondary school students who used cannabis in the past year, the objective of our study was to assess how solitary cannabis use, frequency of use, and age of initiation were associated with varying modes of consumption among male and female youth. The most common mode of cannabis use was smoking; however, over one third of youth who used cannabis reported using multiple modes. Students in our sample who engaged in solitary cannabis use, used at greater frequencies, and initiated use before the age of 14 were more likely to use by multiple modes. Our findings highlight the role that social contexts may play in determining cannabis use patterns and associated risks among youth.

To our knowledge, this has been the first study to assess how solitary cannabis use may be differentially associated with modes of cannabis use. More than a third of students in our sample reported using cannabis alone—and as previously reported, this was most common among males (Creswell et al., 2015; Noack et al., 2011). While the overall prevalence of solitary cannabis use in our sample was similar to observations made in a clinical adolescent setting (Creswell et al., 2015), it was generally higher than what has been previously found in other school-based samples (McCabe et al., 2014; Tucker et al., 2006). We also found that students who engaged in solitary cannabis use were more likely to use cannabis via multiple modes (i.e., via smoking, edibles, and/or vaping) compared to smoking only. Recent evidence from Spinella and colleagues (Spinella et al., 2019) shows that the context in which cannabis is used is an important indicator of higher-risk cannabis use behaviors.

Our stratified analyses revealed few gender-based differences in the association between risky cannabis use behaviors and mode of use. In the stratified models, the magnitude of effect was slightly higher among female students than males when estimating the likelihood of multiple modes among students who engaged in solitary use, but this difference was not statistically different (Supplementary File C). Existing evidence points toward gender-based differences in youth cannabis use. For example, compared to female youth, males tend to use cannabis more frequently (Cuttler et al., 2016; Foster et al., 2016; Legleye et al., 2014) and in greater volumes (Anderson et al., 2015); although, these gaps appear to be narrowing over time (Greaves and Hemsing, 2020; Johnson et al., 2015). Interestingly, female students who engaged in solitary cannabis use were more than twice as likely to exclusively use edibles than females who used cannabis with peers, yet this effect was not observed among males. This is in line with qualitative findings that have pointed to motivations such as avoiding smelling like cannabis smoke or avoiding publicly presenting as using cannabis among females (Friese et al., 2016). Consumption of edible cannabis products has been tied to increased risk of engaging in other substance use behaviors, including illicit substance use and misuse of prescription drugs (Fedorova et al., 2019). Neither male nor female students who reported solitary cannabis use were likely to be exclusively vaping, but solitary cannabis use was shown to interact with gender such that females were significantly less likely to vape exclusively. This finding may support claims that vaping behaviors among youth occur as a social practice (Keane et al., 2017; Yule and Tinson, 2017), but further research is required.

Male and female students who used cannabis at greater frequencies were more likely to use by multiple modes. This is consistent with existing evidence that multiple product use may be associated with more frequent use (Krauss et al., 2017); although, the direction of this association remains unclear given our use of cross-sectional data. Additional analyses using longitudinal data are required to further explore the association between risky cannabis use behaviors (i.e., more frequent, younger, and/or solitary use) and use of cannabis via multiple or alternative modes, rather than smoking only. As noted by Gunn and colleagues (Gunn et al., 2020), it is important to further assess cannabis use patterns with additional indicators (e.g., quantity, product, mode) that can describe individuals’ use, beyond use status or frequency alone; doing so can allow for closer investigation of the impact that specific use behaviors may have on cannabis-related outcomes. Males and females who used cannabis more often were also less likely to use edibles only, consistent with findings from Reboussin and colleagues (Reboussin et al., 2019), and this was shown to interact with gender in the full sample model The same was true for males and exclusive use of vaping; those who used cannabis more frequently were less likely to vape only.

Earlier age of cannabis use initiation was additionally associated with multiple modes of use. Given that we relied on data collected recently from a school-based adolescent sample, these findings may reflect contemporary shifts in cannabis use trends given increased market availability of cannabis products through legalization in Canada. Older students in our study were significantly less likely to use cannabis by vaping only than smoking only. According to these findings, it is possible that older students prefer smoking as that was the mode available to them when they started using cannabis, whereas newer and more novel cannabis vaping products may appeal to newer and younger users. However, younger cannabis use initiation was notably associated with lower odds of vaping cannabis only among males, and lower odds of using edibles only among females. Researchers have noted a surge in the prevalence of vaping behaviors among youth as cannabis and nicotine vaping products have become increasingly accessible (Miech et al., 2021, 2020; Patrick et al., 2020). Using COMPASS data, Doggett and colleagues (Doggett et al., 2021) recently found that the rate of cannabis use by vaping peaked earlier for females during adolescence, and that the rate of vaping cannabis was higher among females than compared to males in grade 9.

A majority of males and females in our sample used cannabis by exclusively smoking it (e.g., via joints, pipes, bongs, etc.). This remains to be the most commonly reported mode of consumption among adolescents (Johnson et al., 2016) and adults (Steigerwald et al., 2018) in other samples. While only a small portion of youth in our sample relied on exclusive use of alternative modes such as either vaping or edibles, use of cannabis via multiple modes was common across gender categories. Consistent with other vaping literature (O'connor et al., 2019), our findings suggest that policies and programs meant to prevent vaping uptake should target younger youth around age of initiation, or ideally beforehand. Moreover, we found that males with more spending money (used here as a proxy for socioeconomic status) were more likely to use cannabis by multiple modes. Previous research has shown that similar to tobacco (Ding, 2003), cannabis price is inversely associated with initiation among youth (Bretteville-Jensen and Williams, 2011; Pacula and Lundberg, 2014; van Ours et al., 2007). Prevention programming should take into account that accessibility is a key determinant of engagement in cannabis use, particularly for youth.

4.1. Strengths and limitations

There are some limitations to note. First, while this study sought to assess the associations between risky cannabis use behaviors and modes of use, we were limited to the measures of cannabis use available to us. The COMPASS study does not collect information about the quantity or potency of cannabis—two important indicators of cannabis use risk. Students who use cannabis in greater quantities and/or greater potency (i.e., higher levels of THC) may be at increased risk of cannabis-related harms and future research should investigate how these factors may be associated with varying modes of use. However, given the relationship between non-combustible cannabis products and greater potency (Hammond, 2019), use of concentrates/vaping and edibles might be considered a proxy for more potent consumption methods compared to cannabis plant or flower consumption. Additionally, the COMPASS study items do not distinguish between vaping cannabis buds/plant material versus cannabis concentrates; therefore, it cannot be determined which specific vaping mode students reported. Solitary cannabis use was also asked within the timeframe of the past month rather in the past year, which would have been consistent with students’ self-reported mode of use. Frequency of cannabis use was also not specific to mode of use, but to overall cannabis use. Results must be interpreted in light of this limitation; students may have endorsed multiple modes of consumption in the last year, yet only one of those modes at least once per month. Relatedly, cannabis use frequency was crudely dichotomized (< 1/month vs ≥ 1/month) according to response distribution and model parsimony. Future research should consider more frequent cannabis use (e.g., daily, weekly) as riskier.

Second, as data used in this study are cross-sectional, we are not able to infer any directional relationship between risky cannabis use behaviors and modes of use. Evidence gathered from longitudinal data would help to identify whether higher-risk behaviors precede use of alternative modes of cannabis, or whether using cannabis via varying modes increases the risk of behaviors such as solitary use and more frequent use. The current COMPASS Y8 data represent the first wave in which questions surrounding solitary use behaviors were included in the Cq – but data collected in future school years will enable additional longitudinal analyses.

Third, in COMPASS Y8, normal data collection procedures were interrupted by the COVID-19 pandemic in March 2020. Usually, data are collected in person throughout the full school year (September-June). Data collection procedures were adapted toward online data collection following COVID-19-related public health measures that included school closures. Findings are also subject to bias as a result of missing data, which was exacerbated by online data collection. Generalizability of the findings to other groups of Canadian youth is thus limited. However, it is worth noting that COMPASS was not designed to be nationally representative, and the high response rate and full school samples support generalizability.

Lastly, the COMPASS Y8 student questionnaire inaccurately used the sex-specific terms “female” and “male” to refer to gender identities. We kept the female/male terminology throughout this report for consistency with the questionnaire, and under the assumption that gender diverse participants would have selected the “I describe my gender in a different way” response option. A subsequent iteration of the questionnaire has since been corrected. Additionally, further research should investigate risky cannabis use among non-binary and gender diverse youth, as our small subsample size in the current study precluded us from doing so. While current research is limited, some evidence suggests higher risk patterns among gender diverse youth. The gender/sex variable also introduces some confounding bias into the interpretation of the results, as it is possible that gender differences (e.g., social motives, gendered perceptions) noted are at least partially driven by biological sex differences (e.g., interactions between THC and sex hormones, telescoping among females) and/or vice versa.

5. Conclusions

We identified that exclusive use of alternative modes of use (i.e., edibles or vaping) was rare; over one third of youth who used cannabis reported using multiple modes. Youth who reported solitary cannabis use, a higher frequency of use, and who initiated cannabis use earlier were more likely to use cannabis via multiple modes. Additionally, females who used cannabis alone were more than twice as likely to exclusively use edibles than to use by smoking only. These findings around solitary use highlight the role social contexts may play in determining cannabis use patterns among youth. As alternative modes of cannabis use become more prevalent in Canada, programs that seek to address cannabis prevention among youth should consider these associations. Future research should examine these associations longitudinally to identify whether risky behaviors precede the use of multiple modes of use or vice versa.

Contributions

IR, AB, GW, and SA conceived the manuscript idea. IR performed the statistical analyses, interpreted the findings, led the manuscript writing, and revised the manuscript for content. AB, GW, and SA drafted components of the manuscript and revised the manuscript for content. KP and SL revised the manuscript for critical content. SL conceived the host study and led the acquisition of data. All authors that have contributed significantly to the work presented within this manuscript has been listed above. All authors have read and approved the final manuscript.

Declaration of Competing Interest

There are no conflicts of interest to declare.

Acknowledgments

The COMPASS study has been supported by a bridge grant from the CIHR Institute of Nutrition, Metabolism and Diabetes (INMD) through the “Obesity Interventions to Prevent or Treat” priority funding awards (OOP-110788; awarded to SL), an operating grant from the CIHR Institute of Population and Public Health (IPPH) (MOP-114875; awarded to SL), a CIHR project grant (PJT-148562; awarded to SL), a CIHR bridge grant (PJT-149092; awarded to KP/SL), a CIHR project grant (PJT-159693; awarded to KP), and by a research funding arrangement with Health Canada (#1617-HQ-000012; contract awarded to SL), a CIHR-Canadian Centre on Substance Use and Addiction (CCSA) team grant (OF7 B1-PCPEGT 410-10-9633; awarded to SL), a project grant from the CIHR Institute of Population and Public Health (IPPH) (PJT-180262; awarded to SL and KP).

Footnotes

Supplementary material associated with this article can be found, in the online version, at doi:10.1016/j.dadr.2022.100101.

Appendix. Supplementary materials

mmc1.docx (21.4KB, docx)

References

  1. Anderson K.G., Sitney M., White H.R. Marijuana motivations across adolescence: impacts on use and consequences. Subst. Use Misuse. 2015;50:292–301. doi: 10.3109/10826084.2014.977396. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Borodovsky J.T., Crosier B.S., Lee D.C., Sargent J.D., Budney A.J. Smoking, vaping, eating: is legalization impacting the way people use cannabis? Int. J. Drug Policy. 2016;36:141–147. doi: 10.1016/j.drugpo.2016.02.022. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bretteville-Jensen A.L., Williams J. Dep. Econ. - Work. Pap. Ser. 2011. Decriminalization and initiation into cannabis use. [Google Scholar]
  4. Bryan A.D., Schmiege S.J., Magnan R.E. Marijuana use and risky sexual behavior among high-risk adolescents: trajectories, risk factors, and event-level relationships. Dev. Psychol. 2012;48:1429–1442. doi: 10.1037/a0027547. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Budney A.J., Sargent J.D., Lee D.C. Vaping cannabis (marijuana): parallel concerns to e-cigs? Addiction. 2015 doi: 10.1111/add.13036. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Cao D., Srisuma S., Bronstein A.C., Hoyte C.O. Characterization of edible marijuana product exposures reported to United States poison centers. Clin. Toxicol. 2016;54:840–846. doi: 10.1080/15563650.2016.1209761. [DOI] [PubMed] [Google Scholar]
  7. Creswell K.G., Chung T., Clark D.B., Martin C.S. Solitary cannabis use in adolescence as a correlate and predictor of cannabis problems. Drug Alcohol Depend. 2015;156:120–125. doi: 10.1016/j.drugalcdep.2015.08.027. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Currie C.E., Elton R.A., Todd J., Platt S. Indicators of socioeconomic status for adolescents: the WHO health behaviour in school-aged children survey. Health Educ. Res. 1997;12:385–397. doi: 10.1093/HER/12.3.385. [DOI] [PubMed] [Google Scholar]
  9. Cuttler C., Mischley L.K., Sexton M. Sex differences in cannabis use and effects: a cross-sectional survey of cannabis users. Canna. Cannab. Res. 2016;1:166–175. doi: 10.1089/can.2016.0010. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Czoli C.D., Hammond D., Reid J.L., Cole A.G., Leatherdale S.T. Use of conventional and alternative tobacco and nicotine products among a sample of Canadian youth. J. Adolesc. Heal. 2015;57:123–125. doi: 10.1016/j.jadohealth.2015.03.006. [DOI] [PubMed] [Google Scholar]
  11. Ding A. Youth are more sensitive to price changes in cigarettes than adults. Yale J. Biol. Med. 2003;76:115–124. [PMC free article] [PubMed] [Google Scholar]
  12. Doggett A., Battista K., Leatherdale S.T. Modes of cannabis use among Canadian youth in the COMPASS study; using LCA to examine patterns of smoking, vaping, and eating/drinking cannabis. Drugs Educ. Prev. Policy. 2021;28:156–164. doi: 10.1080/09687637.2020.1769560. [DOI] [Google Scholar]
  13. Dragt S., Nieman D.H., Becker H.E., Van De Fliert R., Dingemans P.M., De Haan L., Van Amelsvoort T.A., Linszen D.H. Age of onset of cannabis use is associated with age of onset of high-risk symptoms for psychosis. Can. J. Psychiatry. 2010 doi: 10.1177/070674371005500308. [DOI] [PubMed] [Google Scholar]
  14. Elton-Marshall T., Leatherdale S.T., Burkhalter R. Tobacco, alcohol and illicit drug use among Aboriginal youth living off-reserve: results from the Youth Smoking Survey. CMAJ. 2011;183 doi: 10.1503/CMAJ.101913. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Fedorova E.V., Schrager S.M., Robinson L.F., Cepeda A., Wong C.F., Iverson E., Lankenau S.E. Illicit drug use and prescription drug misuse among young adult medical cannabis patients and non-patient users in Los Angeles. Drug Alcohol Depend. 2019;198:21–27. doi: 10.1016/j.drugalcdep.2019.01.026. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Foster K.T., Li N., McClure E.A., Sonne S.C., Gray K.M. Gender differences in internalizing symptoms and suicide risk among men and women seeking treatment for cannabis use disorder from late adolescence to middle adulthood. J. Subst. Abuse Treat. 2016;66:16–22. doi: 10.1016/j.jsat.2016.01.012. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Freeman T.P., Winstock A.R. Examining the profile of high-potency cannabis and its association with severity of cannabis dependence. Psychol. Med. 2015;45:3181–3189. doi: 10.1017/S0033291715001178. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Friese B., Slater M.D., Annechino R., Battle R.S. Teen use of marijuana edibles: a focus group study of an emerging issue. J. Prim. Prev. 2016 doi: 10.1007/s10935-016-0432-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Gorey C., Kuhns L., Smaragdi E., Kroon E., Cousijn J. Age-related differences in the impact of cannabis use on the brain and cognition: a systematic review. Eur. Arch. Psychiatry Clin. Neurosci. 2019 doi: 10.1007/s00406-019-00981-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Government of Canada, 2020. Canadian Cannabis Survey 2020: summary [WWW Document]. URL https://www.canada.ca/en/health-canada/services/drugs-medication/cannabis/research-data/canadian-cannabis-survey-2020-summary.html#shr-pg0 (accessed 6.9.21).
  21. Greaves L., Hemsing N. Sex and gender interactions on the use and impact of recreational cannabis. Int. J. Environ. Res. Public Health. 2020;17:509. doi: 10.3390/ijerph17020509. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Gunn R.L., Aston E.R., Sokolovsky A.W., White H.R., Jackson K.M. Complex cannabis use patterns: associations with cannabis consequences and cannabis use disorder symptomatology. Addict. Behav. 2020;105 doi: 10.1016/j.addbeh.2020.106329. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Hammond D. Communicating THC levels and “dose” to consumers: implications for product labelling and packaging of cannabis products in regulated markets. Int. J. Drug Policy. 2019 doi: 10.1016/j.drugpo.2019.07.004. 1–0. [DOI] [PubMed] [Google Scholar]
  24. Canada Health. A framework for the legalization and regulation of cannabis in Canada: the Final Report of the Task Force on Cannabis Legalization and Regulation. Drug Test Anal. 2016 [Google Scholar]
  25. Johnson R.M., Brooks-Russell A., Ma M., Fairman B.J., Tolliver R.L., Levinson A.H. Usual modes of marijuana consumption among high school students in Colorado. J. Stud. Alcohol Drugs. 2016;77:580–588. doi: 10.15288/jsad.2016.77.580. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Johnson R.M., Fairman B., Gilreath T., Xuan Z., Rothman E.F., Parnham T., Furr-Holden C.D.M. Past 15-year trends in adolescent marijuana use: differences by race/ethnicity and sex. Drug Alcohol Depend. 2015;155:8–15. doi: 10.1016/j.drugalcdep.2015.08.025. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Keane H., Weier M., Fraser D., Gartner C. Anytime, anywhere’: vaping as social practice. Crit. Public Health. 2017;27:465–476. doi: 10.1080/09581596.2016.1250867. [DOI] [Google Scholar]
  28. Kim H.S., Hall K.E., Genco E.K., Van Dyke M., Barker E., Monte A.A. Marijuana tourism and emergency department visits in Colorado. N. Engl. J. Med. 2016;374:797–798. doi: 10.1056/nejmc1515009. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Krauss M.J., Rajbhandari B., Sowles S.J., Spitznagel E.L., Cavazos-Rehg P. A latent class analysis of poly-marijuana use among young adults. Addict. Behav. 2017;75:159–165. doi: 10.1016/j.addbeh.2017.07.021. [DOI] [PubMed] [Google Scholar]
  30. Leatherdale S.T., Brown K.S., Carson V., Childs R.A., Dubin J.A., Elliott S.J., Faulkner G., Hammond D., Manske S., Sabiston C.M., Laxer R.E., Bredin C., Thompson-Haile A. The COMPASS study: a longitudinal hierarchical research platform for evaluating natural experiments related to changes in school-level programs, policies and built environment resources. BMC Public Health. 2014;14:331. doi: 10.1186/1471-2458-14-331. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Legleye S., Piontek D., Pampel F., Goffette C., Khlat M., Kraus L. Is there a cannabis epidemic model? Evidence from France, Germany and USA. Int. J. Drug Policy. 2014;25:1103–1112. doi: 10.1016/j.drugpo.2014.07.002. [DOI] [PubMed] [Google Scholar]
  32. Lemberger L., Weiss J.L., Watanabe A.M., Galanter I.M., Wyatt R.J., Cardon P.V. Delta-9-Tetrahydrocannabinol. N. Engl. J. Med. 1972;286:685–688. doi: 10.1056/nejm197203302861303. [DOI] [PubMed] [Google Scholar]
  33. Markowitz S., Tauras J. Even For teenagers, Money does not Grow on trees: Teenage Substance use and Budget Constraints. 2006 doi: 10.3386/w12300. [DOI] [Google Scholar]
  34. McCabe S.E., West B.T., Veliz P., Frank K.A., Boyd C.J. Social contexts of substance use among U.S. high school seniors: a multicohort national study. J. Adolesc. Heal. 2014;55:842–844. doi: 10.1016/j.jadohealth.2014.06.017. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Miech R., Leventhal A., Johnston L., O'Malley P.M., Patrick M.E., Barrington-Trimis J. Trends in use and perceptions of nicotine vaping among US Youth from 2017 to 2020. JAMA Pediatr. 2021 doi: 10.1001/jamapediatrics.2020.5667. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Miech R.A., Patrick M.E., O'Malley P.M., Johnston L.D., Bachman J.G. Trends in reported marijuana vaping among US adolescents, 2017-2019. JAMA - J. Am. Med. Assoc. 2020 doi: 10.1001/jama.2019.20185. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Noack R., Höfler M., Lueken U. Cannabis use patterns and their association with DSM-IV cannabis dependence and gender. Eur. Addict. Res. 2011;17:321–328. doi: 10.1159/000333338. [DOI] [PubMed] [Google Scholar]
  38. O'connor, S., Pelletier, H., Bayoumy, D., Schwartz, R., 2019. E-Cigarette Use for Smoking Cessation Interventions to Prevent Harms from Vaping Report for the Central East TCAN.
  39. Pacula R.L., Lundberg R. Why changes in price matter when thinking about marijuana policy: a review of the literature on the elasticity of demand. Public Health Rev. 2014 doi: 10.1007/bf03391701. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Patrick M.E., Miech R.A., Kloska D.D., Wagner A.C., Johnston L.D. Trends in Marijuana vaping and edible consumption from 2015 to 2018 among adolescents in the US. JAMA Pediatr. 2020 doi: 10.1001/jamapediatrics.2020.0175. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Reboussin B.A., Wagoner K.G., Sutfin E.L., Suerken C., Ross J.C., Egan K.L., Walker S., Johnson R.M. Trends in marijuana edible consumption and perceptions of harm in a cohort of young adults. Drug Alcohol Depend. 2019;205 doi: 10.1016/j.drugalcdep.2019.107660. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Romano I., Williams G., Butler A., Aleyan S., Patte K.A., Leatherdale S.T. Psychological and behavioural correlates of cannabis use among Canadian Secondary School Students: findings from the COMPASS Study. Can. J. Addict. 2019;10:10–21. doi: 10.1097/CXA.0000000000000058. [DOI] [Google Scholar]
  43. SAS Institute, 2016. SAS 9.4.
  44. Schauer G.L., King B.A., Bunnell R.E., Promoff G., McAfee T.A. Toking, vaping, and eating for health or fun: marijuana use patterns in adults, U.S., 2014. Am. J. Prev. Med. 2016;50:1–8. doi: 10.1016/j.amepre.2015.05.027. [DOI] [PubMed] [Google Scholar]
  45. Shiplo S., Asbridge M., Leatherdale S.T., Hammond D. Medical cannabis use in Canada: vapourization and modes of delivery. Harm Reduct. J. 2016;131(13):1–10. doi: 10.1186/S12954-016-0119-9. 2016. [DOI] [PMC free article] [PubMed] [Google Scholar]
  46. Spinella T.C., Stewart S.H., Barrett S.P. Context matters: characteristics of solitary versus social cannabis use. Drug Alcohol Rev. 2019;38:316–320. doi: 10.1111/dar.12912. [DOI] [PubMed] [Google Scholar]
  47. Steigerwald S., Wong P.O., Cohen B.E., Ishida J.H., Vali M., Madden E., Keyhani S. Smoking, vaping, and use of edibles and other forms of marijuana among U.S. adults. Ann. Intern. Med. 2018 doi: 10.7326/M18-1681. [DOI] [PMC free article] [PubMed] [Google Scholar]
  48. Stuyt E. The problem with the current high potency THC Marijuana from the perspective of an addiction psychiatrist. Mo. Med. 2018;115:482–486. [PMC free article] [PubMed] [Google Scholar]
  49. Thompson-Haile A., Bredin C., Leatherdale S. Waterloo, ON; 2013. Technical Report Series. [Google Scholar]
  50. Tucker J.S., Ellickson P.L., Collins R.L., Klein D.J. Does solitary substance use increase adolescents’ risk for poor psychosocial and behavioral outcomes? A 9-year longitudinal study comparing solitary and social users. Psychol. Addict. Behav. 2006;20:363–372. doi: 10.1037/0893-164X.20.4.363. [DOI] [PubMed] [Google Scholar]
  51. Tucker J.S., Pedersen E.R., Miles J.N.V., Ewing B.A., Shih R.A., D'Amico E.J. Alcohol and marijuana use in middle school: comparing solitary and social-only users. J. Adolesc. Heal. 2014;55:744–749. doi: 10.1016/j.jadohealth.2014.06.015. [DOI] [PMC free article] [PubMed] [Google Scholar]
  52. Van der Pol P., Liebregts N., De Graaf R., Ten Have M., Korf D.J., Van den Brink W., Van Laar M. Mental health differences between frequent cannabis users with and without dependence and the general population. Addiction. 2013;108:1459–1469. doi: 10.1111/add.12196. [DOI] [PubMed] [Google Scholar]
  53. van Ours J.C., Williams J., van Ours J.C., Williams J. Cannabis prices and dynamics of cannabis use. J. Health Econ. 2007;26:578–596. doi: 10.1016/j.jhealeco.2006.10.001. [DOI] [PubMed] [Google Scholar]
  54. Wills T.A., Knight R., Williams R.J., Pagano I., Sargent J.D. Risk factors for exclusive e-cigarette use and dual e-cigarette use and tobacco use in adolescents. Pediatrics. 2015;135:e43–e51. doi: 10.1542/peds.2014-0760. [DOI] [PMC free article] [PubMed] [Google Scholar]
  55. Yingst J.M., Lester C., Veldheer S., Allen S.I., Du P., Foulds J. E-cigarette users commonly stealth vape in places where e-cigarette use is prohibited. Tob. Control. 2019;28:493–497. doi: 10.1136/tobaccocontrol-2018-054432. [DOI] [PMC free article] [PubMed] [Google Scholar]
  56. Yule J.A., Tinson J.S. Youth and the sociability of “Vaping. J. Consum. Behav. 2017;16:3–14. doi: 10.1002/cb.1597. [DOI] [Google Scholar]
  57. Zahra E., Darke S., Degenhardt L., Campbell G. Rates, characteristics and manner of cannabis-related deaths in Australia 2000–2018. Drug Alcohol Depend. 2020;212 doi: 10.1016/j.drugalcdep.2020.108028. [DOI] [PubMed] [Google Scholar]
  58. Zuckermann A.M.E., Williams G.C., Battista K., Jiang Y., de Groh M., Leatherdale S.T., AME Z., GC W., K B., Y J., M de G. Prevalence and correlates of youth poly-substance use in the COMPASS study. Addict. Behav. 2020;107 doi: 10.1016/j.addbeh.2020.106400. [DOI] [PubMed] [Google Scholar]

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