Substance Use and Addiction Services

Substance use and addiction services concern the prevention, identification, and support of people who use alcohol and other drugs in ways that harm health, and the systems of care — from screening and brief intervention to treatment and harm reduction — that respond. For community and public health nursing it is a population-health field that meets people across a spectrum from hazardous use to substance use disorder.

Definition

Substance use disorder is a condition in which recurrent use of alcohol or other drugs causes clinically significant impairment, including health problems, failure to meet responsibilities, and loss of control over use; addiction services are the prevention, screening, treatment, and harm-reduction systems that respond to substance use across its spectrum of severity.

Scope

This entry covers how substance use and substance use disorders are understood, the framing of addiction as a chronic relapsing condition, population approaches such as screening and brief intervention, and the principles of harm reduction. It is reference-educational and non-prescriptive; it gives no dosing, treatment, or individualised clinical advice.

Core questions

• How is the spectrum from hazardous use to substance use disorder defined and identified?
• What does the brain-disease model of addiction add to, and how is it debated against, social and behavioural understandings?
• How do population approaches such as screening and brief intervention work, and what is the evidence for them?
• What are the principles and aims of harm reduction in services for people who use drugs?

Key concepts

• Spectrum of use: hazardous, harmful, and disordered
• Substance use disorder
• Brain-disease model of addiction
• Screening, brief intervention, and referral to treatment (SBIRT)
• Harm reduction
• Relapse and chronic-disease framing
• Stigma and access to care

Mechanisms

Substance use disorders are understood as arising from the interaction of a substance's effects on brain reward, motivation, and self-control circuitry with genetic, developmental, psychological, and social vulnerabilities. The brain-disease model, articulated by Volkow and colleagues, frames severe addiction as a chronic, relapsing condition involving lasting changes in neural circuits, while emphasising that social context and environment strongly shape risk and recovery. Services span the spectrum: population screening and brief intervention aim to identify and reduce hazardous use early, while harm-reduction approaches seek to reduce the health and social damage of ongoing use without requiring abstinence as a precondition.

Clinical relevance

For community and public health nurses, this topic explains why substance use is a population-health issue requiring early identification, low-threshold access, and attention to stigma, and how service models are organised. It is descriptive orientation to the field and its evidence; it provides no dosing or treatment instructions and is not a basis for managing any individual's care.

Epidemiology

Hazardous and harmful substance use is common in the general population and is a leading contributor to the global burden of disease, injury, and premature death. Unhealthy alcohol use in particular is highly prevalent and frequently undetected in routine care, which is why systematic screening in adults has been recommended (US Preventive Services Task Force, 2018). Substance use also concentrates among, and compounds the difficulties of, other vulnerable groups such as people experiencing homelessness.

Evidence & guidelines

The brain-disease model is summarised by Volkow, Koob, and McLellan (2016). The US Preventive Services Task Force (2018) recommends screening and brief behavioural counselling for unhealthy alcohol use in adults, and the WHO ASSIST package supports screening and brief intervention for a range of substances in primary care (WHO, 2010). Harm-reduction services such as needle and syringe programmes and opioid agonist treatment are supported by extensive evidence and reflected in many national and WHO guidelines. This entry summarises the framing only and is not itself clinical guidance.

History

Understanding of problematic substance use shifted over the twentieth century from primarily moral and criminal framings toward medical and public-health ones. Brief-intervention research and the SBIRT model developed from the 1980s onward, harm reduction gained ground amid the response to HIV among people who inject drugs, and the brain-disease model became influential from the 1990s and 2000s, each contributing to how contemporary services are organised and debated.

Debates

The brain-disease model versus social and choice-based understandings

The brain-disease model frames severe addiction as a chronic medical condition and has helped reduce blame and support treatment access, but critics argue it can understate the role of social context, agency, and recovery without treatment; the balance between biological and social framings remains contested.

Key figures

• Nora Volkow
• George Koob
• A. Thomas McLellan

Seminal works

• volkow-2016
• uspstf-2018-alcohol

Frequently asked questions

What is harm reduction?

Harm reduction is an approach that seeks to reduce the health and social harms of substance use — for example through needle and syringe programmes or overdose-prevention measures — without requiring people to stop using as a precondition of care; abstinence may be a goal but is not a gatekeeping requirement.

What does screening and brief intervention mean?

It is a population approach in which people are routinely screened for hazardous or harmful substance use and, where indicated, offered a short structured conversation and, if needed, referral to further treatment; it is designed to identify and reduce risky use early rather than only after a disorder is established.