Few would challenge the proverbial wisdom: ‘a stitch in time saves nine’. In antiquity, Hippocrates said that the function of protecting and developing health must rank above that of restoring it when it is impaired (Foege, 1997). Recast in modern health philosophy: ‘prevention is better than cure’. To prevent, efforts must be applied pre- event (Stoker, 2001). Here, screening plays a central role.
Screening for actual or potential disease or disability has enormous intuitive appeal. A physician diagnosing incurable cancers laments the means of advancing the diagnosis for early detection and preventive medical therapy. The possibility of screening people before they develop a condition, or at an early stage of a disorder, was a revolutionary prospect that became popular in the 1960s (National Health Committee, 2003). Today, health care systems worldwide routinely administer a range of screening activities across the lifespan. To prevent development of disease, premature death and disability, and to improve quality of life and reduce suffering, the case for screening as a primary obligation of public health is compelling and can be argued on rational, economic, moral, political, ethical, and humanitarian grounds. Ergo, a shift in focus from traditional diagnosis and treatment of illness and its complications towards prevention, early detection and modification of risk factors, and management of disease precursors or early disease is occurring globally (NHC, 2003). Screening is pivotal in this important new paradigm.
As in other treatment fields, historical approaches to alcohol and other drug (AOD) problems exemplify a kaleidoscope of changing paradigms about the nature of substance use problems and the most appropriate and effective way to respond to those affected. Until the 1980s, the biomedical disease model of addiction prevailed with its clear dichotomy between the alcoholic versus the social drinker, the non-drug user and
‘the drug addict’, with no allowance for a continuum of harm that includes non- problematic, social/recreational or low-risk use of substances (Saunders, 2002a). In the traditional medical model, addiction/dependence supported individual-directed solutions, tertiary treatment and rehabilitation attempts to cure, giving little place to prevention and the Screening and Early Intervention (SEI) traditions of public health (Edwards, 1992).
In the last 25 years, however, a philosophical shift in the AOD field has occurred, discrediting traditional orthodoxy and bringing “a new vision of the cause of concern” (Lader, Edwards, & Drummond, 1992):
The idea which for too long held sway, that the exclusive focus for concern relating to misuse of alcohol or drugs should be with ‘the addict’, is now clearly ripe for abandonment. We have instead to take within our field of vision the much more extensive array of people who at some point in their lives, with some frequency or persistence, with any degree of severity, experience this or that adverse consequence of drinking or drug taking. From that shift in vision many practical implications flow (p. 189).
Growing dissatisfaction with escalating costs of modestly effective specialist programmes and health care attributable to substance-related morbidity coincided with a re-conceptualisation of the nature of drug consumption and related problems. As a result, the alcoholic/social drinker and addict/non-drug user dichotomy has been replaced with the concept of a continuum of use and misuse of substances (Institute of Medicine, 1990a). The far end of the continuum includes dependence, with a gradient of abuse/misuse and risky use that encompasses a greater proportion of the population and associated problems (IOM, 1990a, 1990b; Kreitman, 1986). When considering the most appropriate time to intervene in the natural history of drug-related problems, the WHO called for efficient methods to detect persons with harmful and hazardous AOD consumption before health and social consequences become pronounced. To correspond to progressive points along the AOD problem severity continuum, a matching continuum of responses was needed, ranging from minimal, through brief interventions, to intensive, specialized treatments (Babor & Higgins-Biddle, 2000; Hall
& Swift, 2006). This necessitated “broadening the base” of interventions to include population-based primary and secondary prevention strategies that could be offered at the primary health care level with a minimum of time and resources, targeting individuals who consume substances at high-risk levels for harms (IOM, 1990a, 1990b). Predicated on the harm minimization philosophy, SEI has emerged as a key component in ‘new public health’ strategies for opportunistic detection and management of drug- related problems in primary health care (WHO, 1998).
Since this historical watershed, the “globalization of brief intervention research” (Drummond, 1997, p. 376) led by researchers in the alcoholism and smoking cessation fields has produced an array of new screening tools and brief interventions (SBI) for alcohol and tobacco use. In stark contrast, similar research attention has not been devoted to SEI approaches for individuals with harmful or risky drug use, most conspicuously - cannabis (Adamson & Sellman, 2003; Alexander, 2003; Copeland, 2004; Hall & Swift, 2006; Paton-Simpson & McKinnon, 2000). Existing drug screens are inadequate for opportunistic detection of both currently problematic and risky cannabis use among consumers of generalist health and social services.
This instrumentation void was the focus of the research reported in this thesis: the development and preliminary evaluation of a brief screen for detecting currently problematic and/or potentially problematic cannabis use among adolescent and adult users in the community to facilitate early intervention to prevent escalation to more serious harms. The following introductory chapters review the cannabis literature and research to provide important background and concepts relevant to the present research. Chapter three outlines screening concepts and principles germane to a Public Health SEI approach to cannabis use problems. Chapter four reviews and evaluates available drug screening technology, generic drug and cannabis-specific screens, with emphasis on these latter ‘new’ screens. The area is then summarized and the research goals specified. The thesis then moves on to development and empirical testing of the draft screener.