48. Illicit Opiate Abuse

Nature, Causes, and Health Consequences of Illicit Opioid Use

Before considering interventions, we briefly summarize what is known about the antecedents, causes, and health consequences of illicit opioid use.

Antecedents of Heroin Use

Law enforcement efforts to reduce the availability of heroin aim to increase its price, deter illicit drug use, and promote social values that discourage heroin use (Fergusson, Horwood, and Lynskey 1998; Hawkins, Catalano, and Miller 1992; Newcomb and Bentler 1988). These gains may be at the cost of increasing harm among the minority who use opioids despite the prohibition—for example, by encouraging injecting use as the most efficient way to use an expensive drug and increasing needle sharing because clean injecting equipment is not freely available (Rhodes and others 2003; Strathdee and others 2003).

Two aspects of the family environment are associated with increased rates of both licit and illicit drug use in young people in developed countries. The first is exposure to a disadvantaged home environment, with parental conflict and poor discipline and supervision; the second is exposure to parents' and siblings' use of alcohol and other drugs (Hawkins, Catalano, and Miller 1992). In developed countries, children who perform poorly in school because of impulsive or problem behavior and those who are early users of alcohol and other drugs are most likely to use illicit opioids (Fergusson, Horwood, and Swain-Campbell 2002). Affiliation with drug-using peers is a risk factor for drug use that operates independently of individual and family risk factors (Fergusson, Horwood, and Lynskey 1998; Hawkins, Catalano, and Miller 1992).

Health Consequences of Heroin Use

The following sections describe the major health consequences of heroin use. They include dependence, increased mortality and morbidity attributable to drug overdoses, and bloodborne viruses.

Heroin Dependence

In household surveys, 1 to 2 percent of adults in Australia, the United States, and Europe report using heroin at some time in their lives (Australian Institute of Health and Welfare 1999; EMCDDA 2002; SAMHSA 2002). The highest rates are typically among adults age 20 to 29. Self-reported heroin use in population surveys probably underestimates rates of use because heroin users are undersampled and those who are sampled underreport their use (W. Hall, Lynskey, and Degenhardt 1999).

In developed countries, one in four of those who report heroin use become dependent on it (Anthony, Warner, and Kessler 1994). People who are heroin dependent continue to use heroin in the face of problems that they know (or believe) to be caused by its use. These problems include being arrested or imprisoned, having interpersonal and family problems, catching infectious diseases, and suffering from drug overdoses. Many heroin users who seek treatment have typically been daily heroin injectors, although in Europe (EMCDDA 2002), North America (Office of National Drug Control Policy 2001), and parts of Asia, illicit opioid users also smoke or "chase" the drug (inhale the fumes released when heroin is heated) (UNODC 2004).

The American Psychiatric Association defines drug dependence as "a cluster of cognitive, behavioral, and physiologic symptoms indicating that the individual continues use of the substance despite significant substance-related problems" (American Psychiatric Association 1994, 176). In the fourth edition of the association's Diagnostic and Statistical Manual of Mental Disorders (1994,), a diagnosis of substance dependence requires that three or more of the following occur together:

At any time in the same 12-month period:

1. tolerance, as defined by either of the following:

   • need for markedly increased amounts of the substance to achieve intoxication or desired effect

   • markedly diminished effect with continued use of the same amount of the substance;

2. withdrawal, as manifested by either of the following:

   • the characteristic withdrawal syndrome for the substance

   • the same (or closely related) substance is taken to relieve or avoid withdrawal symptoms;

3. the substance is often taken in larger amounts or over a longer period than was intended;

4. there is a persistent desire or unsuccessful efforts to cut down or control substance use;

5. a great deal of time is spent in activities necessary to obtain the substance (e.g., visiting multiple doctors, driving long distances), use the substance (e.g., chain smoking), or recover from its effects;

6. important social, occupational, or recreational activities are given up or reduced because of substance use;

7. the substance use is continued despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by the substance.

Indirect estimation methods suggest that in Australia, the United Kingdom, and the European Union fewer than 1 percent of adults age 15 to 54 are heroin dependent (EMCDDA 2002; W. Hall and others 2000). Research in the United States indicates that dependent heroin users who seek treatment or who come to the attention of the legal system may use heroin for decades (Goldstein and Herrera 1995; Hser, Anglin, and Powers 1993), with periods of use punctuated by abstinence (Bruneau and others 2004; Galai and others 2003), drug treatment, and imprisonment (Gerstein and Harwood 1990). When periods of abstinence are included, dependent heroin users use heroin daily for 40 to 60 percent of the 20 years that they typically are addicts (Ball, Shaffer, and Nurco 1983; Maddux and Desmond 1992).

Illicit opioid use increased in Asia, Europe, and Oceania and, to a lesser extent, in Africa and South America in the 1990s, but it has stabilized or declined since 2000 (UNODC 2004). Most illicit opioid users (7.8 million) live in Asian countries that surround the major opium-producing countries, Afghanistan and Myanmar. Europe accounts for about 25 percent of illicit opioid use (4 million users or 0.8 percent of the adult population age 15 to 64). Two-thirds of users are in Eastern Europe, which reported large increases in illicit opioid use during the second half of the 1990s (Atlani and others 2000; Hamers and Downs 2003; Kelly and Amirkhanian 2003; Rhodes and others 1999; Uuskula and others 2002).

Illicit opioid use stabilized in much of Asia between 2000 and 2002 (UNODC 2004) as a result of decreased opium production after the rapid expansion during the 1990s (Dorabjee and Samson 2000; Reid and Crofts 2000). After 2000, India and Pakistan reported stabilizing rates of illicit opioid use but increased injection of pharmaceutical opiates (Ahmed and others 2003; Dorabjee and Samson 2000; Strathdee and others 2003). China has reported a steady rate of growth in illicit opiate use in its southern and northern provinces (Beyrer 2003; Beyrer and others 2000; Yu and others 1998) and a 15-fold increase in the number of registered opioid addicts between 1990 and 2002, bringing the total to about 1 million (UNODC 2004).

Oceania experienced a marked rise in heroin use in the late 1990s, largely driven by a dramatic increase in the availability of heroin in Australia (Darke, Topp, and others 2002; W. Hall, Degenhardt, and Lynskey 1999). In late 2000, an abrupt heroin shortage resulted in a large reduction in fatal and nonfatal overdoses (Day and others 2004; Degenhardt, Day, and Hall 2004).

Mortality, Morbidity, and Heroin Dependence

In developed countries, dependent heroin users have an increased risk of premature death from drug overdoses, violence, suicide, and alcohol-related causes (Darke and Ross 2002; Goldstein and Herrera 1995; Vlahov and others 2004). Heroin users treated before the HIV epidemic were 13 times more likely to die prematurely than their peers (Hulse and others 1999), with opioid overdose the most frequent cause of death (W. Hall, Degenhardt, and Lynskey 1999). In countries with a high prevalence of HIV infection, AIDS is a major cause of premature death among drug users (EMCDDA 2002; UNAIDS and WHO 2002). Fatal opioid overdose deaths increased in many developed countries during the 1990s before declining after 2000 (UNODC 2004).

In parts of Asia, Eastern Europe, and the United States, the sharing of contaminated injecting equipment accounts for a substantial proportion of new HIV infections (EMCDDA 2002; UNAIDS and WHO 2002; UNODC 2004). Injecting opioid use has been a major driver of HIV epidemics in China (Yu and others 1998), Myanmar (Beyrer and others 2000), the Russian Federation and former Soviet republics (Hamers and Downs 2003), and Vietnam (Beyrer and others 2000; Hien and others 2001).

The prevalence of infection with hepatitis B and C viruses among injecting drug users is greater than 60 percent in Australia (National Centre in HIV Epidemiology and Clinical Research 1998), Canada (Fischer and others 2004), China (Ruan and others 2004), the United States (Fuller and others 2004), and the European Union (EMCDDA 2002). Chronic infection occurs in 75 percent of infections, and 3 to 11 percent of chronic hepatitis C virus carriers develop liver cirrhosis within 20 years (Hepatitis C Virus Projections Working Group 1998).

Heroin-related deaths primarily occur among young adults and account for a large number of life years lost in developed societies. In Australia in 1996, for example, such deaths accounted for 2.2 percent of life years lost, with each death accounting for 22 years of life lost (Mathers, Vos, and Stephenson 1999). In Scotland and Spain, opiate-related deaths account for 25 to 33 percent of deaths of young adult males (EMCDDA 2002).

Economic Costs of Illicit Opioid Use

In Canada, Xie and others (1996) calculate the costs of illicit drugs as 0.2 percent of gross domestic product (GDP). In Australia, Collins and Lapsley (1996) estimate the economic costs of illicit drug abuse at 2 percent of GDP.