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Cannabis Use, Anxiety, and Perceptions of Risk among Canadian Undergraduates

The Moderating Role of Gender

Hellemans, Kim G.C. PhD1; Wilcox, Jessica BA3; Nino, Julian N. BSc1; Young, Matthew PhD2,3; McQuaid, Robyn J. PhD4

doi: 10.1097/CXA.0000000000000059
ORIGINAL ARTICLES
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ABSTRACT As nonmedical cannabis is now legal in Canada, it is important to understand the complex relationship between perceptions of risk, problematic cannabis use and mental health among young adults.

Objectives: To assess whether perceptions of risk associated with cannabis relates to cannabis use among young adults. Moreover, we explored whether current symptoms of anxiety were also related to problematic use, and the role of gender in this relationship.

Methods: Self-report surveys were completed by 1043 Carleton University students. Students completed several questionnaires assessing perceptions of risk associated with cannabis use, and cannabis use and anxiety symptoms.

Results: Males were significantly more likely to rate some of the harms associated with cannabis use as less risky, and reported higher rates of cannabis use. We also found that problematic cannabis use was positively related to anxiety symptoms, and this relationship was moderated by gender such that greater cannabis use related to higher anxiety scores more strongly among females.

Conclusions: Our study yields valuable information regarding how Canadian youth perceive the risks associated with cannabis use; critically, males are more likely to perceive minimal risk with use and are also more likely to use problematically. By contrast, cannabis use is more strongly related to anxiety among females. These results have important implications for education and outreach campaigns associated with the legalization of cannabis and cannabis products in Canada.

Comme le cannabis non médical est maintenant légal au Canada, il est important de comprendre la relation complexe entre les perceptions du risque, la consommation problématique de cannabis et la santé mentale des jeunes adultes.

Objectifs: Évaluer si les perceptions de risque associé au cannabis sont liées à la consommation de cannabis chez les jeunes adultes. De plus, nous avons examiné si les symptômes d’anxiété actuels étaient également liés à une utilisation problématique et le rôle du genre dans cette relation.

Méthodes: Des sondages d’auto-évaluation ont été effectués par 1 043 étudiants de l’Université de Carleton. Les élèves ont rempli plusieurs questionnaires évaluant les perceptions du risque associé à la consommation de cannabis, à la consommation de cannabis et aux symptômes d’anxiété.

Résultats: Les hommes étaient beaucoup plus susceptibles de juger certains risques liés à la consommation de cannabis comme moins dangereux et ont signalé des taux de consommation de cannabis plus élevés. Nous avons également constaté que la consommation problématique de cannabis était positivement liée aux symptômes d’anxiété, cette relation étant modérée en fonction du sexe, de sorte qu’une plus grande consommation de cannabis était associée à des scores d’anxiété plus élevés chez les femmes.

Conclusions: Notre étude fournit des informations précieuses sur la manière dont les jeunes Canadiens perçoivent les risques associés à la consommation de cannabis. De manière critique, les hommes sont plus susceptibles de percevoir un risque minimal avec l’utilisation et sont également plus susceptibles de l’utiliser de manière problématique. En revanche, la consommation de cannabis est davantage liée à l’anxiété chez les femmes. Ces résultats ont des implications importantes pour les campagnes d’éducation et de sensibilisation associées à la légalisation du cannabis et des produits à base de cannabis au Canada.

1Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada

2Department of Psychology, Carleton University, Ottawa, Ontario, Canada

3Canadian Centre on Substance Use and Addiction, Ottawa, Ontario, Canada

4The Royal's Institute of Mental Health Research, Ottawa, Ontario, Canada

Corresponding Author: Dr Kim G.C. Hellemans, PhD, Chair, Department of Neuroscience, Health Sciences Building, Room 5302, 1125 Colonel By Drive, Ottawa, ON, Canada K1S 5B6. Tel: +1 613 520 2600x2973; e-mail: kim_hellemans@carleton.ca

The authors report no conflicts of interest.

Received December 21, 2018

Accepted July 9, 2019

This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0

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INTRODUCTION

As nonmedical cannabis is now legal in Canada, it is important to understand perceptions of risk associated with cannabis and how these perceptions relate to patterns of use. This is even more important to understand among young adults (18–24-year olds), who report the highest rate of past-year cannabis use.1 While there may be some medical benefits associated with cannabis products,2,3 frequent use of high-tetrahydrocannabinol (THC) cannabis has been associated with a number of harms, including mental health problems such as cannabis use disorders (CUDs), psychosis and schizophrenia, and in some instances depressive and anxiety disorders.4 Moreover, given the potential long-term effects on the developing brain,5,6 frequent cannabis use among adolescents and young adults (such as in the current university sample) is of concern. However, to our knowledge there have been no previous studies that have examined how perceptions of risk relate to use patterns among Canadian university students. Moreover, there is little to no information on how perceptions of risk might differ between males and females, and whether these differences relate to harms associated with use. In this study, we explored this relationship by surveying a population of undergraduate students, enrolled at Carleton University in Ottawa, Canada during the 2016 to 2017 academic year (i.e., prelegalization).

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Perceptions of Risk of Cannabis Use

Qualitative research exploring perceptions of cannabis among Canadian youth (aged 14–19) revealed that many youth perceive harms associated with cannabis to be minimal.7 For example, many young Canadians believe cannabis is safer than other drugs, including alcohol, which may explain the high rates of use among this age group.8 Moreover, many youth believe there is no danger in driving while under the influence of cannabis; in fact, many argue that it “helps [them] focus.”7 As McInnis and Porath-Waller9 reported, these beliefs are reflected in the number of Canadian students who appear to be driving while high, posing a risk to both themselves and others in their community. Moreover, a number of the youth interviewed indicated they thought cannabis is “good” and “safe” to use, because it is a natural substance.7 In addition, some youth also believe that cannabis is safer than prescription drugs used to treat mental health disorders,7 suggesting they may be more inclined to use cannabis as a form of self-medication. Indeed, there is a strong body of evidence that individuals with elevated levels of anxiety and patients with anxiety disorders report using cannabis to relieve their anxiety symptoms.10,11 Taken together, these qualitative data suggest that some youth, before legalization, perceive minimal harm to no harm associated with cannabis use. This is important as a national report in the United States shows that perceived risks are considered a leading indicator of trends of use.12 Moreover, given evidence that legalization/decriminalization of cannabis products has been associated with decreased perceptions of risk, and concomitant increased use,13–16 it is important to monitor use before and after legalization in Canada—especially among university-aged Canadians.

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Cannabis Harms and Gender

Heavy cannabis users (generally defined as daily or near daily use17) are more frequently male.18,19 Moreover, CUDs are more prevalent among younger male adults20,21 and among individuals who initiated use at a younger age compared to middle-aged and older adults.21 This finding is concerning, due to the association between frequent cannabis use and poor physical and mental health outcomes.22 Individuals who use cannabis daily are also at the highest risk of experiencing these negative outcomes.23 Among youth in Canada aged 20 to 24 who reported using cannabis over the past 12 months, 22.5% reported cannabis daily use,24 with males having the highest rates.

By contrast, anxiety disorders25 are more prevalent among females, and the relationship between cannabis use and anxiety is complex. In this regard, trait anxiety seems to be associated with increased regular cannabis use, and cannabis use also is associated with elevated baseline anxiety levels,26,27 although not all reports show this relationship.28 However, up to 25% of individuals with CUD report experiencing social anxiety, and individuals with at least 1 anxiety disorder are twice as likely to use cannabis.28,29 Thus, it is not clear whether cannabis use promotes anxiety symptoms among some individuals or if individuals self-medicate their anxiety with cannabis products, thereby increasing the likelihood of engaging in problematic cannabis use. Further complicating this relationship is the fact that some individuals report increased levels of anxiety and panic with acute cannabis use,30 and anxiety may also be experienced during withdrawal.25 This, in turn, could further motivate individuals to use cannabis as a means of alleviating these symptoms. Given the increased risk among females for the development of anxiety disorders, the exact nature of how gender moderates the relationship between cannabis use and anxiety is of interest.

The present study was designed to assess (1) the relationship between perceptions of risk associated with cannabis and cannabis use among Canadian University students; (2) whether self-reported anxiety scores were positively related to cannabis use; and (3) whether gender moderated these relationships. It was hypothesized that problematic cannabis use would be associated with reduced perceptions of risk of cannabis use, such as the belief that cannabis is not addictive or that there are few health risks associated with its use. Moreover, we hypothesized that self-reported anxiety symptoms would be associated with increased cannabis use.

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METHODS

Procedure

Undergraduate students from Carleton University in Ottawa, Canada were recruited through the university's online computerized research system. This online system comprises mainly first-year students. Once participants signed-up, they completed an online informed consent form and an online survey, which included a series of questionnaires measuring perceptions of risk associated with cannabis use, current cannabis use, current anxiety symptoms, and a series of demographic questions (e.g., age, gender, ethnicity). Critically, the data collection phase was done prelegalization, to achieve a benchmark of risk perception before legalization. After completing the questionnaires, participants received a written debriefing and were compensated with course credit. This study was approved by the Carleton University Research Ethics Board.

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Measures

Perceptions of Risk Associated with Cannabis

To assess participants’ perceptions regarding cannabis use, student responded to statements using a 4-point Likert scale. Some examples include “Marijuana can be harmful to your mental health” and “People can get addicted to Marijuana.” A full list of the questions asked to participants can be found in Table 1.

Table 1

Table 1

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Problematic Cannabis Use

Cannabis use was assessed using the Cannabis Use Disorder Identification Test-Revised (CUDIT-R31). It is an 8-item survey including questions, such as “How often do you use Marijuana?” and “How often in the past 6 months have you had a problem with your memory or concentration after using Marijuana?”. Total scores were calculated by summing across all items (α = 0.89). The total score was used for most analyses. However, severity of CUD was also used for some analyses. Associated with the CUDIT-R is a coding algorithm that categorizes respondents into categories describing the extent of any CUD. These are mild (9), moderate (11), and severe (13) cases of CUD.32

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Anxiety

Anxiety levels were assessed using the Beck Anxiety Inventory. This is a 21-item, self-report scale that contains questions related to symptoms of anxiety, such as “Unable to Relax,” “Heart Pounding/Racing,” and “Faint/Lightheaded.” Participants rated how often they have experienced the specific symptoms in the past month using a 4-point scale (ranging from 0 = “Not At All” to 3 = “Severely—It Bothered Me A Lot”). Total scores were calculated by summing across all items (α = 0.94).

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Statistics

Statistical analyses were performed using SPSS for Windows 24.0 (SPSS Science, Chicago, IL). Statistical significance was determined at P < 0.05 (2-tailed). Analyses assessing sex differences in anxiety scores, perceived stress and problematic cannabis use were assessed using independent samples t tests, the P value for equal variances not assumed was reported when Levene's test was significant (P < 0.05). Correlational analysis was performed using Pearson product moment correlations. Moderation analyses were conducted through model 1 in PROCESS.33

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RESULTS

Participants (N = 1043) in the present study had a mean age of 20.0 years and included 62.5% females (n = 652), 37.2% males (n = 388), and 0.3% (n = 3) identified their gender as other. Due to the small number of individuals who identified their gender as other, we were not able to include them in any gender specific analyses. The majority reported their ethnic/racial background as white (57.4%), followed by Black (9.7%), Arab/West Asian (9.4%), Asian (8.6%), South Asian (4.9%), Indigenous (2.3%), South East Asian (2.0%), Latin American/Hispanic (1.4%), and other (4.2%).

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Perceptions of Cannabis

Students’ perceptions of risk associated with cannabis use were examined by gender (Table 1). A number of the perceptions surrounding cannabis did not differ according to gender. In this regard, the majority of males and females felt that cannabis can be harmful to physical, and mental health, and that cannabis can be addictive, but there were no gender differences in this regard, χ2 (1) = 0.73, P = 0.39, χ2 (1) = 3.39, P = 0.06, and χ2 (1) = 1.45, P = 0.23, respectively. A large majority of participants also reported that cannabis can reduce anxiety and that it is safer than other recreational drugs such as lysergic acid diethylamide (LSD) or ecstasy; however, males and females did not differ in this perception, χ2 (1) = 0.63, P = 0.43 and χ2 (1) = 0.79, P = 0.38, respectively. Moreover, while roughly half of males and females believed that cannabis can make people anxious, once again there were no gender differences, χ2 (1) = 0.02, P = 0.89.

While the majority of both males and females also felt that cannabis is safer than alcohol, a higher percentage of males reported this, χ2 (1) = 14.12, P < 0.001. A higher percentage of males were also more likely than females to report that cannabis is safe to use while pregnant, χ2 (1) = 4.39, P = 0.04, and that it is safe to drive under the influence of cannabis, χ2 (1) = 17.35, P < 0.001. However, less than 15% of participants agreed with these statements. Finally, a greater percentage of females reported that cannabis is risky compared to males, χ2 (1) = 18.13, P < 0.001.

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Perceptions of Cannabis and Problematic Cannabis Use

It was of interest to examine which perceptions of cannabis most strongly related to problematic cannabis use (CUDIT-R) scores. A multiple regression analysis was conducted containing each of the cannabis perceptions in relation to the CUDIT-R. The overall multiple regression model was significant, R2 = 0.20, R2adj = 0.19, F (10, 1032) = 25.73, P < 0.001. As shown in Table 2, the perception that cannabis can be addictive, cannabis is safer than alcohol, it is safe to drive under the influence of cannabis, cannabis makes people anxious and cannabis is risky were significant predictors of CUDIT-R scores.

Table 2

Table 2

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Problematic Cannabis Use and Anxiety

Males reported higher problematic cannabis use compared to females [t(685.88) = −3.71, P < 0.001] (Mean [M] = 4.5, Standard Error [SE] = 0.30 vs M = 3.2, SE = 0.19, respectively). Moreover, when examining problematic cannabis use according to the CUDIT-R cutoff scores (Table 3), almost half of females (48.6%) reported no use of cannabis, and 7.7% reported severe problematic use. For males 44.3% reported no use, whereas 14.4% reported severe problematic use. When examining symptoms of anxiety, female participants reported higher anxiety [t(943) = 8.72, P < 0.001] (M = 18.8, SE = 0.52), compared to males (M = 12.3, SE = 0.54).

Table 3

Table 3

Students who had a family history of anxiety were more likely to report problematic cannabis use [t(464.44) = −3.43, P = 0.001] (M = 4.62, SE = 0.34) compared to those with no family history of anxiety (M = 3.29, SE = 0.18). Moreover, those with a family history of anxiety reported first using cannabis at an earlier age compared to those without a family history χ2 (4) = 38.66, P < 0.001. In this regard, among those with a family history of anxiety, 32.5% reported using cannabis before 16 years of age, whereas only 18.2% reported this among those with no family history. Moreover, 64.9% with a family history reported using cannabis before the age of 18 years, whereas only 46.5% reported this among those with no family history of anxiety.

There was a weak correlation between problematic cannabis use CUDIT-R scores and anxiety, r = 0.15, P < 0.001. However, it was hypothesized that this relationship might be dependent upon gender. A moderation analysis showed that gender did moderate the relationship between problematic cannabis use and anxiety, R2change = 0.01, F (1, 1036) = 6.99, P < 0.01, such that higher scores of problematic cannabis use was associated with higher anxiety scores, but that this relationship was stronger for females, B = 0.61, t = 6.23, P < 0.001, 95% confidence interval (CI) (4.19, 8.05), compared to males, B = 0.24, t = 2.28, P < 0.05, 95% CI (0.33, 0.44) (Fig. 1). Moreover, when the alternative model was tested with anxiety as the independent variable and problematic cannabis use as the dependent variable, the moderation analyses was no longer significant, P = 0.75.

Fig. 1

Fig. 1

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DISCUSSION

Together, our results revealed several interesting findings. As predicted, perceptions of cannabis use differed according to gender. In general, males had more liberal attitudes to use, perceiving it to be less risky than females. This finding was not surprising, given that females are more likely to perceive greater risk associated with cannabis use than males,19,34 and are overall more risk averse.35,36 In addition, it is noteworthy that our study was in-line with previous research indicating males were more likely to report problematic cannabis use than females.19

Regarding perceptions of risk, individuals that disagreed with the statements “cannabis can be addictive” and “cannabis is risky” were more likely to have higher scores on the CUDIT-R. Moreover, high scores on the CUDIT-R were significantly related to the belief that “cannabis is safer than alcohol” and it is “safe to drive under the influence of cannabis.”37 Though it may be argued that, indeed there are fewer harms associated with cannabis than alcohol,38 these data suggest individuals who use cannabis more problematically are more likely to downplay the harms associated with frequent use.39 Identifying specific perceptions that most strongly predict problematic cannabis use might inform possible areas for intervention, which is important given the recent cannabis legalization in Canada.

Our results are consistent with the literature that females overall have higher anxiety scores relative to males.40,41 Further, there was a relationship between greater problematic cannabis use and higher anxiety symptoms, and this relationship was stronger for females. Moreover, when testing the alternative model (i.e., flipping anxiety scores to the predictor variable and CUDIT-R to the outcome), the moderation model was no longer significant. These findings align with those suggesting, among females, risk of developing an anxiety disorder increases as cannabis use increases.42 Interestingly, a recent prospective study using a Dutch adolescent cohort explored the moderating effect of the serotonin transporter gene (5-HTTLPR) on the relationship between anxiety and cannabis use. This study revealed that cannabis use significantly increased self-reported anxiety symptoms over time, but only among individuals with the short allelic variation.43 Future studies could explore whether females with the short allelic variation are at even greater increased risk of cannabis use associated anxiety.

Our results also indicated that individuals with a family history of anxiety were more likely to report frequent cannabis use and CUD. In addition, participants who reported a family history of anxiety were more likely to start using cannabis at a younger age, which increases the risks of experiencing negative mental and physical health effects from cannabis.44 While the etiology of anxiety disorders is complex, there is a strong body of evidence suggesting that there is some familial relationship, likely through a combination of genetic and environmental factors.45 Though some individuals with anxiety may be self-medicating with cannabis, ironically it is possible that these individuals may be at risk of developing an anxiety disorder if they use high THC products and consume frequently.5 Education and intervention campaigns should focus on providing targeted messages around the effects of using cannabis products, particularly for prevention efforts among individuals with a family history of psychiatric disorders, as they should be aware that they may be at greater risk for the development of anxiety, depression, and possibly psychotic disorders. In addition, these messages should target healthcare practitioners, to ensure they are discussing the effects of cannabis with their patients.

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LIMITATIONS AND FUTURE DIRECTIONS

Important limitations of the present study is that participant's mental health and cannabis use habits were all self-reported and cross-sectional, thus precluding any causal interpretations. As our study was conducted when cannabis was still illegal, it is possible that participants did not truthfully report their use. In addition, there is a negative stigma surrounding cannabis use that may have prompted participants to underreport their use. Stigma may have also impacted reports of psychiatric disorders and levels of anxiety, such that individuals may have failed to report a diagnosis of anxiety or may have reported feeling less anxious than they truly did. Moreover, information regarding an exact age of first use and the potency of the products used would have been beneficial.

The present study presents many opportunities for future research to better understand the relationship between cannabis use and anxiety symptoms, as well as perceptions of harms among university students. For instance, as cannabis use patterns change in Canada,8 it would be beneficial to consider how university students in different provinces may perceive cannabis. In addition, as the present study primarily focused on first year students, it would be interesting to see how perceptions of cannabis change throughout the various years of study. Finally, it would be valuable to conduct a similar study now that nonmedical cannabis is legal in Canada, given that our data were collected prelegalization. As the present study suggests, there is a substantial need for further education on the effects of cannabis (both harms and benefits), and it would be beneficial to see how perceptions of cannabis have changed following legalization, especially within the vulnerable populations previously discussed.

Taken together, our data reveal a number of novel findings related to perceptions of risk, cannabis use, and gender among a Canadian University sample. Based on our findings, intervention and education campaigns could be focused on targeting males for the risks associated with cannabis use associated with heavier use, and for females regarding problematic use and the link with anxiety.

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Keywords:

anxiety; cannabis; gender; university students; youth; anxiété; cannabis; sexe; étudiants universitaires; jeunes

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