Substance Use by Canadian Youth - A National Survey of Canadians' Use of Alcohol and Other Drugs - Canadian Addiction Survey (CAS)

Chapter 5: Other Drug Use and Harms

Highlights

• Among youth, cannabis was the most frequently reported drug used during one's lifetime (61.4%), followed by hallucinogens (16.4%), then cocaine (12.5%), ecstasy (11.9%), speed (9.8%) and inhalants (1.8%). The lifetime use of each of inhalants, heroin, steroids and drugs by injection was about 1%.
• A greater percentage of youth than adults reported use of any of 5 illicit drugs (24.2% versus 15.2%) and any of 6 illicit drugs in their lifetime (62.1% versus 42.3%).
• The rate of lifetime and past-year illicit drug use other than cannabis (24.2% and 11.3%, respectively) was highest among 18- to 19-year-olds and youth from the Quebec region. In addition, the rate of lifetime and past-year illicit drug use including cannabis (62.1% and 37.9%, respectively) was also higher among 18-to 19-year-olds and youth from the Quebec region.
• Youth who had used in their lifetime were more likely than adults to report harm from their use of any of 8 illicit drugs (34.5% versus 20.7%) or any of 5 illicit drugs (59.5% versus 41.7%).

Introduction

The focus of this chapter is on the use of drugs other than cannabis in youth. The lifetime and past-year prevalence of 8 drug-use behaviours: cocaine or crack; hallucinogens, PCP or LSD; speed or amphetamines; heroin; ecstasy (MDMA) or other similar drugs; inhalants (glue, gasoline or other solvents); steroids; and injection drug use, along with various concerns related to their use, will be explored.

Lifetime prevalence is based on the question asking respondents whether they "ever used or tried" the given drug, and past-year prevalence is based on a follow-up question about whether they also used the drug at least once in the past 12 months.

In addition, six derived variables were examined: (1) any lifetime and past-year use of any of 6 illicit drugs, including cannabis (cannabis; cocaine or crack; hallucinogens, PCP or LSD; speed or amphetamines; heroin; ecstasy [MDMA]); (2) any lifetime and past-year use of any of 5 illicit drugs, excluding cannabis; and (3) any lifetime and past-year use of any of 8 drugs (including steroids and inhalants). The rationale for examining use of any of 5 illicit drugs in addition to any of 6 or any of 8 is because the variables any of 6 and any of 8 include those respondents who have used cannabis in their lifetime or past year. Since approximately 62% of youth have used cannabis in their lifetime, and about 37% have done so in the past year, use of cannabis blurs the results for use of the other illicit drugs. As such, examining use of any of 5 illicit drugs allows the examination of those youth who have engaged in an even less common activity--those who have used any of the 5 main illicit drugs. Examining use of any of 8 drugs allows us to examine the proportion of youth who have used at least one illicit substance when taking into account all possible substances (cocaine, speed, ecstasy, heroin, hallucinogens, cannabis, steroids and inhalants).

To examine age at first use of the different drugs, all those who had used in their lifetime were asked the question, "How old were you when you first started using [drug name]?"

The consequences and harms caused by drug use were examined in youth 15 to 24 years of age. These harms can take several forms, including the general harms to one's physical and social well-being (e.g. negative effects on friendships and social life, work and family) and symptoms that put people at risk for substance use disorders (e.g. uncontrolled use, impaired functioning).

The CAS assessed general harms with eight items reported during one's lifetime and during the 12 months before the survey. These eight items reflect whether the respondent felt that his or her drug use had a harmful effect on his or her (1) friendships and social life, (2) physical health, (3) home life and marriage, (4) work and studies, (5) financial position, (6) legal problems, (7) housing and (8) learning.

Results

Lifetime and Past-Year Prevalence of Use

Table 5.1, as replicated from the detailed report (Adlaf et al., 2005), presents the rates of lifetime use of the various illicit drugs by age. The rate of use of ecstasy was higher among youth than older age groups, with 10.1% aged 15 to 19 and 13.4% aged 20 to 24 reporting lifetime use, in comparison with 4.1% overall. In addition, the rate of reported use of cannabis, hallucinogens, cocaine, at least one of 5 illicit drugs, at least one of 6 illicit drugs and at least one of 8 illicit drugs peaked among the 20- to 24-year-old group and then decreased from age 25 onwards.

Figure 5.1 highlights this change in the prevalence rates across age. The figure shows that while the rates do not vary greatly, there is a steep increase between age 15 and 17, and 18 and 19 in the proportion of respondents who have used any drugs in their lifetime, and then the proportion begins a steady decline after age 19 onwards.

Figure 5.1: Change in lifetime prevalence across age

Overall, 61.4% of youth have used cannabis in their lifetime, 16.4% have used hallucinogens, 12.5% have used cocaine, 11.9% have used ecstasy, 9.8% have used speed, and 1.8% have used inhalants (Table 5.2). Females were less likely than males to use hallucinogens in their lifetime (12.2% versus 20.4%) and any of 5 illicit drugs in their lifetime (20.8% versus 27.4%).

Youth 20 to 24 years of age were more likely than 15-to 19-year-olds to have used cannabis (68.5% versus 53.4%), cocaine (15.0% versus 9.8%), hallucinogens (19.2% versus 13.2%), any of 5 illicit drugs (28.1% versus 19.8%), any of 6 illicit drugs (69.3% versus 54.0%), or any of 8 illicit drugs (69.5% versus 54.1%) in their lifetime (Table 5.2). Generally, females were less likely than males to have used illicit substances in their lifetime. There were no differences in past 12-month use of any of these substances between youth aged 15 to 19 and those 20 to 24 years of age. In terms of gender differences for past 12-month use, there were no differences between males and females aged 15 to 19 for illicit drug use. For those aged 20 to 24 years, however, males were more likely than females to have used cannabis (42.0% versus 30.7%), any of 5 illicit drugs (16.8% versus 5.9%), any of 6 illicit drugs (43.8% versus 31.1%), or any of 8 illicit drugs (43.9% versus 31.1%) in the past 12 months (Table 5.2).

Regarding differences in lifetime use between the age categories 15 to 17, 18 to 19 and 20 to 24 (Table 5.3), 18- to 19-year-olds were more likely than 15- to 17-year-olds to have used cannabis (69.9% versus 39.3%), hallucinogens (21.0% versus 6.5%), any of 5 illicit drugs (30.6% versus 10.5%), any of 6 illicit drugs (70.9% versus 39.5%) and any of 8 illicit drugs (70.9% versus 39.6%) in their lifetime. There were no differences in lifetime illicit drug use between youth 18 to 19 and 20 to 24 years of age. Youth 18 to 19 years of age were more likely than those 15 to 17 and 20 to 24 to have used cannabis in the past 12 months (47.2% versus 29.2% and 36.5%, respectively). In addition, youth 18 to 19 were more likely than those 15 to 17 to currently have used any of 5 illicit drugs (17.8% versus 5.2%), any of 6 illicit drugs (48.6% versus 29.5%) and any of 8 illicit drugs (48.6% versus 29.6%). Youth aged 20 to 24 were less likely than 18- to 19-year-olds to have used any of 6 illicit drugs (37.6% versus 48.6%) or any of 8 illicit drugs (37.7% versus 48.6%) in their lifetime. There were no differences for any substance use between males and females aged 15 to 17. Generally, for youth 18 to 19 and 20 to 24, males had a higher prevalence of use than females. This reflects the finding for cannabis that was displayed in the previous chapter, in which there is no sex difference near the age of initiation.

Characteristics Associated with Lifetime and Past-Year Use of Any of 5 Illicit Drugs

When controlling for all demographic characteristics, there was a significant main effect of sex, age and region in predicting lifetime use of any of 5 illicit drugs among youth (cocaine, speed, ecstasy, hallucinogens, heroin) (Table 5.4). Males were more likely than females (27.4% versus 20.8%), youth aged 15 to 17 were less likely than those 18 to 19 and 20 to 24 years of age (10.5% versus 30.6% and 28.1%, respectively), and youth from the Atlantic and Ontario regions were less likely (17.6%) and those from Quebec (35.9%) were more likely to have used any of 5 illicit drugs in their life.

Regarding past-year use of any of 5 illicit drugs among youth, there were significant main effects again in terms of sex, age and region (Table 5.5). Males were almost two times more likely than females to be current users of any of 5 illicit drugs (14.8% versus 7.5%). In addition, as with lifetime use, youth 18 to 19 years of age were more likely than those 15 to 17 years of age to have used any of 5 drugs in the past 12 months (17.8% versus 5.2%); as opposed to lifetime use; however, those aged 20 to 24 were less likely than 18-to 19-year-olds to report past 12-month use of any of 5 illicit drugs. Youth from the Quebec region were more likely than those from the rest of Canada to currently use any of 5 illicit drugs (17.6%).

Characteristics Associated with Lifetime and Past-Year Use of Any of 6 Illicit Drugs

In terms of the characteristics of youth reporting lifetime use of any of 6 illicit drugs (cannabis, cocaine, speed, ecstasy, hallucinogens, heroin), there were significant main effects of age and region (Table 5.6). Youth 18 to 19 years of age were more likely than those aged 15 to 17 to have used any of 6 illicit drugs in their lifetime (70.9% versus 39.5%), and youth from the Atlantic region were less likely (51.9%) and those from the Quebec region more likely (73.8%) to have done so.

Regarding current use of any of 6 illicit drugs, there were significant main effects of sex, age, region and household location when taking all the demographic characteristics into account (Table 5.7). Unlike that for lifetime use of any of 6 illicit drugs, males were more likely than females to be current users (42.5% versus 33.2%). In addition, as with lifetime use, youth 18 to 19 years of age were also more likely than those 15 to 17 years of age to currently use any of 6 illicit drugs (48.6% versus 29.5%); however, unlike that demonstrated for lifetime use, youth 20 to 24 years of age were less likely than 18- to 19-year-olds (37.6% versus 48.6%) to do so. Youth from the Quebec region were more likely than those from the rest of Canada to currently use any of 6 illicit drugs (47.4%), and those from non-rural households were more likely than those from rural households to currently do so (39.4% versus 27.9%).

Age of First Use

For purposes of policy and intervention, the mean age of use of the various illicit drugs (cannabis, speed, hallucinogens, ecstasy) was examined (Table 5.8). For these substances, youth generally started using cannabis at the earliest age; the mean age of cannabis use among youth was slightly less than 16 years, and this was followed by hallucinogens at 17 years, speed at slightly less than 18 years, cocaine at 18 years and ecstasy at a little over 18 years. Overall, there were no differences between males and females in the mean age of first use of the various substances.

Reasons for Using/Not Using Illicit Drugs

Respondents who had used at least one illicit drug at least once in their lifetime were asked, "Thinking of the very first time you used the drug(s) you mentioned, what was the single most important reason why you started using it/them?" Almost half of youth (49.3%) stated that the single most important reason for starting to use drugs was "to try out or because of curiosity". This was followed by "to get high" stated by 11.2% of youth and because "family or friends are using" stated by 10.8%.

To examine why people who try drugs continue to use them, respondents who had used drugs in the past 3 months were asked, "What is the most important reason why you are still using it/them? The most common response to this question among youth was that they "didn't know" why they are still using them (19.7%), followed by "for recreation purposes" (17.7%) and "to get or feel high" (10.3%).

To examine the reasons why some youth never used illicit drugs, those who had never used any illicit drugs in their lifetime were asked, "What is the single most important reason why you don't use drugs?" The most frequent response among youth was "because it is a health risk" (40.0%), followed by "because I am not interested in drugs" (30.4%) and "drugs are addictive" (5.5%).

Harms and Problems

Table 5.9 presents the percentage of users who have reported lifetime harms from their use of any of 8 drugs (cannabis, cocaine, speed, hallucinogens, ecstasy, inhalants, heroin, steroids). Users were asked if they have experienced harms in their lifetime as a result of their drug use on friendships and social life; physical health; home life or marriage; work, studies or employment opportunities; financial position; legal problems; housing; or learning.

A higher percentage of youth than adults reported lifetime harms as a result of their drug use on their friendships and social life (14.8% versus 9.3%); physical health (20.3% versus 13.5%); home life or marriage (11.4% versus 7.8%); work, studies or employment opportunities (13.4% versus 7.8%); financial position (12.0% versus 7.3%); learning (9.6% versus 4.9%), and experienced one or more types of harm overall in their lifetime as a result of their drug use (34.5% versus 20.7%). There were no differences between youth 15 to 19 years of age and those 20 to 24 years of age in terms of lifetime reported harms. When examining all the different types of harms combined, however, 15- to 19-year-olds were more likely than those aged 20 to 24 to have reported experiencing at least one harm in their lifetime resulting from their drug use (41.2% versus 29.9%).

Table 5.10 presents the proportion of users who have experienced harms from use of any of 5 illicit drugs (cocaine, speed, hallucinogens, ecstasy, heroin) in their lifetime. Similarly, a higher proportion of youth than adults reported harms due to their use of drugs in the areas of physical health (39.9% versus 27.6%); work, studies or employment opportunities (26.2% versus 16.8%); financial position (26.5% versus 17.6%); learning (18.5% versus 10.1%), and a higher proportion reported at least one or more types of harms in their lifetime (59.5% versus 41.7%). Within the youth subgroups, again there were no differences between those 15 to 19 years of age and those 20 to 24 years of age in any of the different types of reported harms, or in the proportion of respondents reporting at least one or more types of harms in their lifetime.

To examine the characteristics of youth who have reported at least one or more problems as a result of their use of any of the 5 illicit drugs (cocaine, speed, ecstasy, hallucinogens, heroin) in their lifetime, a multivariate logistic regression was conducted taking into account sex, age, region, household location and income adequacy (Table 5.11). Overall, there were no differences in terms of sex, age, region, household location or income between those youth who reported problems and those who did not, among the lifetime users.

Summary and Discussion

Excluding cannabis, hallucinogens are the most prevalent illicit drug used in the lifetime by youth, followed by cocaine, ecstasy, speed and inhalants. When examining lifetime and past 12-month use of illicit drugs across age, there is a peak for the prevalence of use among those aged 18 to 19, after which age the prevalence of use begins a steady decline.

As is the case with alcohol and cannabis use, youth are not a homogeneous group in terms of their illicit drug consumption: 18- to 19-year-olds were more likely than those aged 15 to 17 to have used illicit drugs in their lifetime, and more likely than 15- to 17- and 20- to 24-year-olds to currently use. In addition, males were in general more likely than females to have used illicit drugs in their lifetime and currently. Youth from the Atlantic and Ontario regions were less likely than those from the rest of Canada to have reported lifetime use of at least one illicit drug, whereas those from the Quebec region were more likely to have reported both lifetime and current use of at least one illicit drug. These findings reflect those demonstrated for alcohol and cannabis use. One potential explanation might be that those who use alcohol and cannabis are more likely to use other illicit drugs, and since those from Quebec are more likely to use alcohol and cannabis and those from the Atlantic region less likely, then we would expect similar patterns for use of illicit drugs. Another possible explanation for this finding could pertain to age of cannabis initiation and its relation to subsequent illicit drug use (Fergusson and Horwood, 2000; Lynskey et al., 2003). Since in the previous chapters we saw that youth from the Atlantic and Ontario regions had later ages of cannabis initiation, whereas those from Quebec had earlier ages, if age of cannabis initiation is linked to subsequent illicit drug use, it should not be surprising that Quebec youth demonstrate higher rates of illicit drug use and those from the Atlantic region demonstrate lower rates. Alcohol and cannabis use as well as age of cannabis initiation will all be examined as predictors of subsequent illicit drug use in the next chapter.

In terms of the age of initiation of illicit drug use, cannabis had the lowest mean age of initiation (M=16) followed by hallucinogens (M = 17), and then speed, cocaine and ecstasy (M = 18). Among youth who had used at least one illicit drug other than cannabis in their lifetime, the most important reason provided for why they started using them, 49.3%, was "to try out or because of curiosity"; however, when asked why they still used, the most common answer provided by almost one fifth of youth was that they "didn't know". Those who had never used any illicit drugs provided "because they are a health risk" as their single most important reason for never doing drugs.