Illicit Opioid Use and Its Key Characteristics: A Select Overview and Evidence from a Canadian Multisite Cohort of Illicit Opioid Users (OPICAN)

Article excerpt

Objectives: To summarize key characteristics and consequences of illicit opioid use from the literature and to present corresponding data from a multisite sample of illicit opioid users in 5 Canadian cities (OPICAN study).

Method: We undertook an overview of recent literature from North America, Australia, and Europe. We obtained data from the multicity OPICAN cohort study, which consisted of an interviewer-administered questionnaire, a standardized mental health instrument (the Composite International Diagnostic Interview Short Form for depression), and saliva-antibody tests for infectious disease (that is, HIV and hepatitis C virus). The baseline sample (n = 679) was collected in 2002.

Results: Illicit opioid use in Canada and elsewhere is becoming increasingly heterogeneous in terms of opioid drugs used, with heroin playing an increasingly minor role; further, it predominantly occurs in a context of polydrug use (for example, cocaine-crack or benzodiazepines). Large proportions of illicit opioid users have physical and (or) mental health comorbidities, including infectious disease and (or) depression, and therefore require integrated interventions. Finally, morbidity risks among illicit opioid users are often predicted by social marginalization factors, for example, housing status or involvement in crime.

Conclusions: Given the epidemiologic profile and high disease burden associated with contemporary forms of illicit opioid use, more effective treatment approaches are urgently needed in Canada and elsewhere. Specifically, treatment must adjust to the extensive polysubstance use realities, yet it must also more effectively address the complex physical and (or) mental health comorbidities presented by this high-risk population.

(Can J Psychiatry 2006;51:624-634)

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Clinical Implications

* Illicit opioid use to a large extent manifests via the illicit use of prescription opioids and typically includes polysubstance use.

* Physical and (or) mental health comorbidities are highly prevalent in illicit opioid user populations.

* Morbidity and (or) mortality risks are often associated with social marginalization.

Limitations

* Little is known about the patterns and consequences of illicit opioid use in general populations.

* Owing to the marginalized and illegal status of illicit opioid users, information is available only from selective populations with limited potential for generalizability of data.

* The OPICAN study specifically builds largely on self-report and may be subject to bias.

Key Words: illicit opioid use, comorbidity, infectious disease, treatment, polysubstance use, dependence, opioid maintenance, social determinants, public health, Canada

Abbreviations used in this article

CIDI-SF Composite International Diagnostic Interview Short Form

HCV hepatitis C virus

IDU injection-drug user

MMT methadone maintenance treatment

Illicit opioid use has been a main element of illicit drug use in North America and other occidental countries for more than a century. However, while the phenomenon has typically been associated with the narrow image of the "heroin junkie" (1), the current reality of illicit opioid use has become much more diverse and complex. Illicit opioid use is associated with considerable risks and harms relating specifically to users' drug use, health, and social problems (for example, crime). Many of these characteristics contribute to the substantive disease, as well as to the social cost, burden of illicit opioid use, making it an important public health problem and underscoring the need for effective interventions (2,3). This paper's objectives are twofold: we selectively present key characteristics and consequences of illicit opioid use, drawing on data from Canada, Australia, Europe, and the United States; and we present corresponding data from a multisite sample of illicit opioid users in 5 Canadian cities (the OPICAN study). …