Best Practices -- Early Intervention, Outreach and Community Linkages for Youth with Substance Use Problems

2. Literature Review

2.1 Patterns of Youth Substance Abuse

Key Points

• Statistics Canada estimated that youth 15 to 24 years of age represented approximately 13.6% of the population in 2005.
• The most frequently used substances are alcohol and cannabis. Initiation rates for illicit substance use tend to peak during adolescence.
• Early initiation of substance use is associated with longer-term problem substance use for both males and females.
• Higher rates of injection drug use are evident among homeless and street youth.

2.1.1 General Prevalence

Statistics Canada estimated that there were approximately 4.4 million youth 15 to 24 years of age, or 13.6% of the population, in 2005 (ages 15--19: 6.6%; ages 20--24: 7.0%). The group aged 10 to 14 years comprises another 6.5% (Statistics Canada, 2006a). Research over the past several decades indicates that between the late 1970s and the early 1990s, substance use among youth declined. However, more recently there has been an increase in problem substance use to the high levels of the early and mid-1970s (Canadian Centre on Substance Abuse [CCSA], n.d.(b)); Health Canada, 2001f). The most frequently used substances by youth are alcohol and cannabis (Health Canada, 2001d). Self-report on past-year use shows that approximately two-thirds have experimented with alcohol and one-third with cannabis (CCSA, n.d.(b)).

The Canadian Addiction Survey (2004) (Adlaf, Begin and Sawka, 2005) (for individuals 15 years and over) indicates there have been significant increases in alcohol and cannabis use since 1994, with people under age 25 accounting for most of the increase (Adlaf et al., 2005). Past-year drinking is highest (90%) among youth aged 18 to 24 years (Adlaf et al., 2005). Past-year cannabis use is 30% for 15- to 17-year-olds and 47% for 18- to 19-year-olds; however, use drops substantially after age 24 (Adlaf et al., 2005). Estimates of illicit drug use are low (at least one of cocaine; speed; ecstasy; hallucinogens; heroin) (3%) for the general population, but higher for 18- to 19-year-olds (18%) and 20- to 24-year-olds (12%) (Adlaf et al., 2005). The Canadian Community Health Survey: Mental Health and Well-being (2002) shows that prevalence of past-year heavy drinking and illicit drug use peaks during the early twenties (60% and 47%, respectively), and frequent episodes (at least monthly) of heavy drinking are common among those aged 20 to 24 (Tjepkema, 2004).

Initiation rates for illicit substances tend to peak during adolescence (Clark, 2004). For many youth, problem substance use decreases or discontinues in young adulthood (American Academy of Child and Adolescent Psychiatry [AACAP], 2005). Longitudinal observations reveal that most youth who start using substances often begin with alcohol. From this point, some progress to using marijuana, with a smaller portion subsequently moving on to harder drugs (AACAP, 2005; Brown and D'Amico, 2001; Health Canada, 2001f). Chronic substance use usually involves multiple substances (Deas, Riggs, Langenbucher, Goldman and Brown, 2000). Several Canadian provinces reported that multiple and concurrent substance use increased during the 1990s (Health Canada, 2001f). In particular, adolescent males have been reported to use a broader array of drugs than their adult counterparts (Deas et al., 2000).

The 2004 Canadian Campus Survey, of full-time undergraduates, indicated that 77% reported using alcohol within the past 30 days. Almost one-third also reported heavy drinking (five or more drinks per episode); this was more common among students living away from home. Cannabis was the next most frequently used substance. Thirty-two percent indicated using cannabis during the past year, and 17% during the past month. Following cannabis, hallucinogen use was reported by 6% of undergraduates during the past year, and opiate use was indicated by 5% (CAMH, 2005).

Survey results of substance use from various territorial and provincial government documents are summarized in Tables 1 and 2. Prevalence estimates of past-year alcohol use varied from 49% in Prince Edward Island to 69% in Quebec (Table 1). Rates of heavy use or binge drinking over the last month ranged between 23% in Ontario and 31% in Alberta (Table 1). Cannabis was the second most reported substance used by youth, with estimates of past-year use varying from 24% in Prince Edward Island to 39% in Quebec. Daily cannabis use was also noted in various reports, ranging from 3% of Ontario students (Grades 7--12) to 9% of Yukon students (Grades 8--12) (Table 1).

Substances less frequently reported by youth included LSD, psilocybin (mushrooms), mescaline, inhalants and cocaine. Survey results showed that use of hallucinogens averaged nearly 10%, while rates for the remaining substances were typically below 6% (Table 2). One limitation to student drug use surveys is that they have limited capacity to show prevalence for youth "out-of-the-mainstream" (Health Canada, 1996, 2001f).

Table 1: Prevalence (%) of Alcohol and Cannabis Use by Students

Province	Alcohol			Cannabis
	Past yearA	Heavy UseB	DrunkennessC	Past YearA	Monthly or Before	Everyday
N.L. 20031	58		36	35	21	5
N.S. 20022	52	29	28	37	16	5
P.E.I. 20023	49			24
N.B. 20024	53			35
Que. 20025	69			39	25	4
Ont. 20056	62	23	22	27		3
Man. 20047	59	25		33	11	4
Alta. 20058	63	31		27
B.C. 20039	57*	26		37*
Y.T. 200110					17	9

Table 2: Prevalence (%) of Other Drug Use in the Past Year by Students

Province	LSD	Tranquilizers	Hallucinogens**	Inhalants	Amphetamine	Ecstasy	Cocaine	Heroin
N.L. 20031	5	3	8	6	5	2	4	1
N.S. 20022	6		12	5	9	4	4	2
P.E.I. 20023	4	4	7	6		4	2	2
N.B. 20024	5	5	12	5	11	4	4	2
Que. 20025			13	2			5	1
Ont. 20056	2	2	7	5	2	5	4	1
Man. 20047				3	3	3
Alta. 20058	2	2	9	3		6	4	1
B.C. 20039			13*	4*	4*		5*	1*
Y.T. 200110	5*		24*	4*		7*	5*

A Students reporting use in the past year

B Defined as binge drinking or consuming five or more drinks in one episode in the past month

C Drank to the point of drunkenness in the last month

* Prevalence based on "ever" having used the substance

** Hallucinogens usually included psilocybin (mushrooms) and mescaline

1 Poulin, Martin and Murray. (2005). Newfoundland and Labrador (Island Portion Only) Student Drug Use Survey 2003 Summary Report.

2 Poulin. (2002). Nova Scotia Student Drug Use 2002 Technical Report. Province of Nova Scotia.

3 Van Til and Poulin. (2002). Prince Edward Island Student Drug Use Survey 2002 Highlights Report.

4 Liu, Jones, Grobe, Balram and Poulin. (2002). New Brunswick Student Drug Use Survey 2002 Highlights Report.

5 Perron and Loiselle. (2003). Portrait of the Situation in 2002 and Main Comparisons with 2000, Quebec Survey of Tobacco Use in High School Students, 2002 (Summary Results), Québec, Institut de la statistique du Québec.

6 Adlaf and Paglia-Boak. (2005). Ontario Student Drug Use Survey Highlights: Drug Use Among Ontario Students -- 1977--2005. Centre for Addiction and Mental Health.

7 Patton, Mackay and Broszeit. (2005). Alcohol and Other Drug Use by Manitoba Students. Manitoba High School Survey 2004. Addictions Foundation of Manitoba.

8 AADAC. (2006). The Alberta Youth Experience Survey (TAYES) 2005 Summary Report.

9 McCreary Centre Society. (2004). Healthy Youth Development: Highlights from the 2003 Adolescent Health Survey III.

10 Government of Yukon Women's Directorate and the Department of Education. (2002). A Capella North 2 (ACN2) 2001. Bulletin 5 Alcohol and Drugs.

2.1.2 Gender-Specific Considerations

Female youth often have a lower threshold than males to the effects of alcohol (Health Canada, 2001f). In addition, female youth tend to experience symptoms of dependence more quickly and are often more susceptible than males to health problems related to alcohol and drug consumption (Poole and Dell, 2005).

Histories of sexual and physical abuse are positively associated with increased substance use and are more frequent among female than male youth (Ballon et al., 2001; Poole and Dell, 2005). Research suggests that some female youth use substances to ameliorate mood, increase confidence, cope with problems, loosen inhibitions, lose weight or enhance sexual experiences (Poole and Dell, 2005).

For most substances, research indicates that male youth are more likely than female youth to use substances at problematic levels (Poole and Dell, 2005). Student drug use surveys reveal that males' substance use is higher for most drugs investigated. Exceptions to this pattern include non-medical stimulants such as diet pills (Health Canada, 2001f). In an Australian study investigating hospital emergency room visits, alcohol use was more prevalent among male than among female youth, whereas prescription medications were more often used by females (Hulse, Robertson and Tait, 2001).

Studies on injection drug use among street youth have revealed conflicting findings, with some reporting higher rates among females than among males, and others reporting lower rates (Health Canada, 2001f; Montgomery et al., 2002). In one study, it was noted that young women were more apt to use protective behaviours such as accessing needle exchange and carrying clean needles. The authors suggested that young women might be more open to receiving interventions to reduce both their own risks and those of their social networks (Montgomery et al., 2002).

2.1.3 Age of Initiation

Early initiation of substance use has been predictive of longer-term problem substance use for both males and females (D'Amico et al., 2001; Health Canada, 2001f; Manning et al., 2001; Simkin, 2002; Sung, Erkanli, Angold and Costello, 2004; Usher, Jackson and O'Brien, 2005). Early onset and a rapid escalation of substance use patterns have also been identified as risk factors for subsequent addictions (AACAP, 2005). In a community sample of youth interviewed at age 12 and again several times before the age of 30, those who drank at an earlier age were more likely to develop alcohol use problems. Heavy first-time use was predictive of greater problems with alcohol (Warner and White, 2003).

Early drinkers are also more likely to develop problems with alcohol and other drugs (Brown and D'Amico, 2001; Grant, Stinson and Harford, 2001; Stueve and O'Donnell, 2005). Studies suggest that early initiation of drug use (before the age of 14) is associated with greater risk for subsequent alcohol and poly-drug use as well as injection drug use (Ellickson, Tucker, Klein and Saner, 2004; Grant et al., 2001; Storr, Westergaard and Anthony, 2005; Sung et al., 2004). One longitudinal study indicated that when onset of alcohol use was delayed, there was a corresponding reduction in alcohol dependence (Grant et al., 2001). Deferred initiation of cannabis and tobacco use also decreased the likelihood of developing subsequent problem substance use (Ellickson and Morton, 1999; Gil, Wagner and Tubman, 2004; Grant et al., 2001).

2.1.4 Alcohol

Alcohol is often the first and the most frequently used substance by Canadian youth (Government of Yukon, 2002; Health Canada, 2001f; Stice, Myers and Brown, 1998). Approximately two thirds of middle and high school students report consuming alcohol at least once in the past year (Health Canada, 2001f). Males were more likely than females to use alcohol (Adlaf and Paglia, 2003). Research suggests that use of alcohol may disinhibit youth and encourage experimentation with other substances (Stice et al., 1998).

In an American sample, initial alcohol use was noted to be more likely to occur in the context of family gatherings. Youth who initiated use outside of family situations were at greater risk of developing later alcohol use problems. Feeling "drunk" upon initial use was also reported to be an important predictor of future problem drinking (Warner and White, 2003).

Levels of use among peers have also been positively associated with alcohol use escalation as well as reduction rates. When peers use, many youth are more inclined to use because of increased accessibility of substances and social acceptance. In contrast, lower levels of use among peers decrease availability, involve less social reinforcement and model more appropriate coping strategies and lifestyles (Stice et al., 1998). Escalation of alcohol use has also been associated with low parental support, negative affect (e.g. anxiety and depression) and internalizing symptoms (e.g. withdrawn behaviours, somatic complaints) (Stice et al., 1998).

Binge or heavy episodic drinking, usually defined as five or more drinks on one occasion for males and four or more for females, has been identified as a common pattern among many adolescents. In a high school sample from California, half were characterized as having been binge drinkers at some point (D'Amico et al., 2001). Researchers have noted that for many youth, binge drinking is a transitory pattern, with youth moving into and out of binge patterns of consumption within a few years (Baer, Kivlahan, Blume, McKnight and Marlatt, 2001; D'Amico et al., 2001).

Binge drinking among high school students has been linked with poorer academic performance and histories of engaging in other risk-taking behaviours (D'Amico et al., 2001). One longitudinal study in Australia indicated that binge drinking in adolescents was a strong predictor of subsequent problems with alcohol use in adulthood (Masterman and Kelly, 2003).

Among adults, alcohol use disorders are sometimes linked with performance decrements in visuo-spatial, locomotor, executive functioning (inhibiting actions, restraining and delaying responses, attending selectively, planning, organizing) and memory functioning (Brown, Tapert, Granholm and Delis, 2000). In particular, executive functioning was observed to have slow recovery from central nervous system exposure to alcohol. In one study of adolescents 15 to 16 years of age, alcohol-dependent youth exhibited neurocognitive deficits in visuo-spatial aspects and in retention of recently acquired information. The researchers commented that such deficits exacerbate academic problems that in turn enhance risk for social problems (Brown et al., 2000).

2.1.5 Cannabis

Among provincial Canadian student drug use surveys, reports of past-year cannabis use varied from 24% in Prince Edward Island to 39% in British Columbia (see Table 1). For many, cannabis use is initiated during later middle school or at the beginning of the secondary level (AADAC, 2006; Patton, Mackay and Broszeit, 2005; von Sydow et al., 2001). In one longitudinal investigation, approximately half of all cannabis users had spontaneously ceased their use by their early twenties; however, cannabis use was linked with the initiation of other illicit substances (von Sydow et al., 2001).

The psychoactive effects of smoking or ingesting cannabis include a sense of well-being, a decrease in inhibitions, difficulty with concentration, and an increase in the perceived intensity of sensations (Roberts, 2003). Some individuals experience anxiety, depression or paranoia. At high doses, panic attacks and hallucinations may occur (Roberts, 2003). Factors predicting initial cannabis use include:

• accessibility;
• male gender;
• low socio-economic status;
• adverse life events;
• concurrent mental health disorders;
• low parental attachment and conflicting family relationships;
• parental substance use problems (von Sydow et al., 2002b);
• poor academic performance (Ellickson et al., 2004).

Research indicates that approximately 66% of 14- to 16-year-olds who are offered cannabis will use it. For those who have ever used, approximately 34% will proceed to regular use (Manning et al., 2001). Higher rates of cannabis use have been noted among street or homeless youth (66% to 88%) (CCSA, n.d.(a)). Factors predicting progression to cannabis abuse and dependence include male gender, younger age, other substance abuse or dependence and early parental loss (von Sydow et al., 2002b).

2.1.6 Volatile Substances/Inhalants

Problematic substance use includes inhaling fumes or vapours from solvents and other volatile substances, such as paint thinner, glue, gasoline, paint, correcting fluid, felt-tip markers and aerosol sprays with gas propellants. Vapours can be inhaled by sniffing from a container, breathing through soaked materials or inhaling concentrated fumes from a bag placed over the mouth. Psychoactive effects include light-headedness, hallucinations, impulsiveness and a brief high. Higher rates of inhalant use have been observed among street youth, inner-city youth and some First Nations and Inuit youth residing in rural and remote areas. Surveys in Canadian secondary schools indicate that most who use volatile substances are between the ages of 10 and 17, with use peaking between 12 and 15 years of age (Dell and Beauchamp, 2006).

Inhalants are often first used during the pre-adolescent years (Health Canada, 2001f). In a British study of youth aged 14 to 16, approximately 44% of those who were offered solvents subsequently initiated use (Manning et al., 2001). Some research indicates that inhalant use is more common among males than among females (MacLean and d'Abbs, 2002).

The Ontario Student Drug Use Survey reported that between 1977 and 2001, prevalence of solvent abuse during a 12-month period for students in Grades 7 to 13 was on average 2.5% (Dell and Garabedian, 2003). The 1998--99 National Longitudinal Survey of Children and Youth asked 12- and 13-year-olds whether their friends had experimented with glue or solvents. Approximately 90% indicated that none of their peers or friends had used solvents; the remaining 10% reported that a few, most, or all their friends had tried solvents (Dell and Garabedian, 2003). Although concerns have been raised in the media about solvent abuse among Canadian Aboriginal peoples, current prevalence is unknown. In a survey of First Nations and Inuit communities, approximately half of all participants who had abused solvents had begun to use them when they were 11 years of age or younger. Approximately 43% of the respondents described themselves as experimental users, 38% referred to themselves as social users and 19% considered themselves chronic users. Approximately 76% of those who used solvents also used alcohol (Dell and Garabedian, 2003).

2.1.7 Non-Medical Use of Prescription and Over-the-Counter Drugs

Surveys of student drug use in Grades 7 to 12 indicate that approximately 7% of females and 5% of males in Ontario reported the non-medical use of stimulants, such as diet pills, during the past year (Adlaf and Paglia, 2003). Non-medical use of amphetamines and/or methylphenidate (Ritalin) was reported by 2% of Alberta youth (AADAC, 2006), 3% of males and females in Ontario (Adlaf and Paglia, 2003) and 12% of females and 14% of males in Nova Scotia students in Grades 7, 9, 10 and 12 (Poulin, 2002). In Manitoba, surveys of students revealed that the prevalence of using other people's prescriptions increased from Grade 7 through to Senior 4, from 2% to 8% for females and from 2% to 5% for males (Patton et al., 2005).

2.1.8 Ecstasy and Other Amphetamines

Youth who use ecstasy and other amphetamines tend to be poly-drug users and often have co-morbid mental health issues (Saskatchewan Health, n.d.; von Sydow et al., 2002a). The chronic use of methamphetamine generally involves a "binge and crash" pattern of behaviour that is accompanied with higher doses and higher frequency of use (Deguire, 2005). Possible long-term effects of methamphetamine include memory loss, difficulty completing complex tasks, inflammation of the heart lining, dental health problems and persistent psychotic symptoms (Deguire, 2005; Saskatchewan Health, n.d.).

Epidemiological reviews indicate that the prevalence of ecstasy use was around 1% among Ontario high school students in 1996 (Smart and Ogborne, 2000). A 1999 Ontario student drug use survey indicated that experimentation with ecstasy among students ranged from less than 1% in Grade 7 to approximately 10% in Grade 11 (Health Canada, 2001f). Surveys conducted in 2001 in Manitoba and in 2003 in Ontario indicated that approximately 3% of senior school students (Manitoba) and 3% of students in Grades 7 though 12 (Ontario) reported using methamphetamine during the past year (Adlaf and Paglia, 2003; Patton, Brown, Broszeit and Dhaliwal, 2001). More recent surveys in Alberta, Manitoba and Ontario reported past-year student rates of methamphetamine use in the range of 2% to 3% (AADAC, 2006; Adlaf and Paglia-Boak, 2005; Patton et al., 2005).

Investigations undertaken with homeless or street youth often report higher prevalence of methamphetamine. In a Vancouver study, 71% of a non-random sample of street youth and young adults (aged 14--30) reported using methamphetamines. Similarly, a Toronto study indicated that 37% of homeless youth used methamphetamine at least once a month (Deguire, 2005). In a recent survey of street youth living in Winnipeg, 41% of males and 33% of females reported using methamphetamine monthly or more often. Daily methamphetamine use was reported by 18% of male and 21% of female youth (Bodnarchuk, Patton and Rieck, 2006).

Regional reports from some Canadian jurisdictions suggest increases in the use of amphetamines among youth. Many provinces have published provincial plans for addressing the problem use of crystal meth and other amphetamines. These strategies have identified target populations of special concern, including street youth, those who attend "rave" dances and youth using methamphetamine to control weight (AADAC, 2004; B.C. Ministry of Health Services, Mental Health and Addictions, 2004; Saskatchewan Health, n.d.).

2.1.9 Opiate, Cocaine and Injection Drug Use

A great proportion of injection drug users is located in large urban centres; however, regional addiction reports suggest increases in opiate use, especially among youth, in rural settings (Ploem, 2000). Opiate use includes heroin, morphine, codeine, methadone, Dilaudid, Demerol and OxyContin. Most of those who use opiates are injection drug users. Opiate users frequently also inject cocaine/crack, amphetamines or other stimulants, and smaller percentages inject steroids, hallucinogens and other substances (Health Canada, 2001e; Ploem, 2000).

Although recent student surveys indicate that a small percentage of youth inject opiates, cocaine or other substances, current data-gathering efforts do not effectively reach those who are not connected with formalized community systems or services. Prevalence of past year injection drug use for in-school students is approximately 1% (Liu et al., 2002; McCreary Centre Society, 2004; Poulin, 2002; Poulin et al., 2005). Individual studies involving street and homeless youth generally report higher rates (Bodnarchuk et al., 2006; Health Canada, 1996, 2001f). Findings from the 2003 Enhanced Surveillance of Canadian Street Youth indicated that lifetime prevalence of injection drug use among street youth was 22% (Public Health Agency of Canada, 2006). A survey of Winnipeg street youth showed lifetime prevalence as 35% for females and 37% for males (Bodnarchuk et al., 2006). The substances most commonly injected included methamphetamine, cocaine, the opiates heroin and morphine, speedball (a mix of cocaine and opiates, usually heroin) and hallucinogens (Bodnarchuk et al., 2006; Public Health Agency of Canada, 2006).

2.1.10 Alcohol Abuse and Dependence

Approximately 8% of young people aged 15 to 24 and 3% of adults aged 25 to 44 experience substance dependence (Statistics Canada, 2003a). Diagnostic decisions pertaining to substance "abuse" and "dependence" are generally formulated according to the adult guidelines/criteria outlined in the DSM-IV and DSM-IV-TR (American Psychiatric Association [APA], 1994; 2001). "Abuse" criteria reflect a maladaptive pattern of substance use that results in significant impairment in functioning (APA, 1994; 2001). Indicators include role impairment, physically hazardous use, and recurrent substance-related legal, social and interpersonal problems (Clark, 2004). Of these areas, symptoms of abuse are most commonly present in the hazardous use and interpersonal domains (Clark, 2004). "Dependence" criteria include continued substance use despite significant substance-related problems, and include features such as blackouts, withdrawal, tolerance and loss of control over intended use (APA, 1994; 2001).

Concerns have been raised about the applicability of DSM criteria to adolescents (American Academy of Child and Adolescent Psychiatry [AACAP], 2005; Brown and D'Amico, 2001; Lopez, Turner and Saavedra, 2005). Some researchers note that in contrast to adults who generally demonstrate a progression from abuse to dependence, adolescent abuse symptoms do not always precede dependence symptoms (Bonomo, Bowes, Coffey, Carlin and Patton, 2004; Brown and D'Amico, 2001; Clark, 2004). Adolescents exhibiting clinically significant problems with alcohol may not qualify for an alcohol use disorder diagnosis.

Symptoms of alcohol withdrawal tend to be experienced less frequently in adolescents until late in their alcohol use disorder (Clark, 2004). Tolerance is a predictor of dependency in adults, but has less applicability for youth (Bonomo et al., 2004; Brown and D'Amico, 2001). Their presentation of tolerance may be different from that of adults (Brown and D'Amico, 2001). Health complications are often chronic in nature and are more frequently experienced by adults than by adolescents (Bonomo et al., 2004). However, youth often experience significant impairment in family functioning and interpersonal relationships, as well as disruptions in school attendance and academic performance (AACAP, 2005).