Managing Polysubstance Use in Clinical Practice: What New Research Tells Us

By Luciana D'Agnone BA, MSc | Director & Editorial Lead - Last reviewed: 10 July 2026

Polysubstance use is one of the most complex challenges facing addiction treatment clinics today. As drug markets evolve faster than traditional monitoring systems can track, frontline clinicians need practical strategies for adapting patient care in real time, sometimes without reliable information about what a patient has actually consumed.¹

In a new paper published in Drug and Alcohol Review (2026), Professor Paul Griffiths and a team of international researchers argue that existing drug surveillance systems are failing to keep pace with a more dynamic, digitally enabled, and globally connected drug market. We spoke with Professor Griffiths who leads addiction research at a number of leading institutions and is featured as an expert contributor here at The OAD Clinic, to explore what these findings mean for clinical practice.

Why Drug Markets Are Changing Faster Than Clinical Systems Can Track

The globalisation of drug supply chains, the rise of digital marketplaces, and the proliferation of synthetic drugs and novel psychoactive substances (NPS) have fundamentally altered the landscape of substance use. Where traditional drug trends once shifted gradually, today's markets can introduce new substances and new patterns of use in a matter of weeks.¹

Yet the systems clinicians and policymakers rely on such as treatment records, population surveys, law enforcement data, are largely retrospective. They capture what happened months or years ago, not what is arriving in communities right now.

The limitations of traditional surveillance data

Professor Griffiths' paper identifies several core weaknesses in how we currently monitor drug use:

• Treatment records only capture people who look for help, missing large portions of the using population

• Population surveys are typically annual or bi-annual, creating significant lag time

• Law enforcement data reflects enforcement priorities as much as actual drug use

• None of these sources reliably captures rapidly emerging substances or shifting polysubstance use patterns

The OAD

Practice

At The OAD Clinic, our clinical team stays current with emerging drug trends through ongoing professional development, peer-reviewed literature review, and clinical supervision. Where patient presentation is complex or unusual, we draw on toxicological data, collateral history, and close monitoring to inform care,  recognising that no single data source tells the whole story.

What This Means for Clinicians Day-to-Day

When asked about practical steps for clinicians working in regions with shifting polysubstance use, Professor Griffiths emphasised that the growing complexity of drug use patterns does not invalidate existing models of care:

"This greater complexity does not mean that existing models of care or core clinical competencies are no longer valid. Rather, there is a need for clinicians to be both more open-minded and more vigilant."

In practical terms, this brings relevance to:

• Maintaining a broad differential when patients present with atypical symptoms

• Being alert to the possibility that patients may not know which substances they have consumed, particularly with pressed tablets, adulterated supplies, or digital market purchases

• Recognising that care decisions may be complicated by the co-consumption of multiple substances, including prescribed medications

• Using available toxicological testing to confirm or challenge self-report where clinically indicated

Why patients may not know what they have taken

The adulteration of street drugs, including the presence of synthetic opioids, novel benzodiazepines, and other substances in supplies not labelled as containing them, means that patient self-report alone is an increasingly unreliable guide to what a patient has been exposed to.¹

For clinicians, this reinforces the value of non-judgemental, open questioning alongside clinical observation, and where feasible, confirmation through testing.

Balancing Automated Data With Patient Self-Reporting

One of the paper's central recommendations is for health systems to invest in more sophisticated, real-time surveillance. For clinical staff, this raises a practical question: how should objective surveillance data be weighted against what patients tell us?

Professor Griffiths' answer is clear: automated data should function as contextual intelligence, not as a replacement for clinical judgement.

"Clinical staff can best balance automated data with patient self-report by using surveillance data as contextual intelligence rather than as a substitute for clinical judgement. The most useful approach is to triangulate data, with self-reports, and clinical assessment to support timely, person-centred care."

How The OAD Clinic approaches clinical assessment in a complex drug landscape

At The OAD Clinic, person-centred assessment sits at the core of our practice. Where surveillance data or clinical intelligence indicates an increase in particular substances in circulation, our clinical team factors this into assessments and treatment planning, using it as a prompt for more detailed history-taking rather than as a diagnostic shortcut.

Toxicological confirmation, where feasible within an appropriate clinical timeframe, provides a useful additional layer. But it supplements, rather than replaces, the therapeutic relationship and clinical judgement that remain central to effective addiction treatment.

Key Takeaways for Addiction Treatment Providers

• Drug markets are evolving faster than traditional surveillance systems. Clinicians should expect to encounter substances and combinations that are not yet well-documented in guidance

• Core clinical competencies remain valid — what is needed is greater vigilance and open-mindedness, not wholesale new frameworks

• Patients may be unaware of what they have consumed — this is particularly true for adulterated or digitally sourced substances

• Surveillance data is a tool to inform, not replace, clinical judgement. It can be best used if triangulated with self-report and direct clinical assessment

• International collaboration and investment in real-time drug monitoring will be essential for more timely, evidence-based clinical guidance going forward

Frequently Asked Questions

What is polysubstance use and why is it clinically significant?

Polysubstance use refers to the concurrent or sequential use of two or more psychoactive substances. It is clinically significant because the combined effects of multiple substances can be unpredictable, can complicate both diagnosis and treatment, and can increase the risk of adverse outcomes including overdose. It also makes it harder to attribute symptoms or changes in presentation to any single substance.

How are drug markets changing and what does this mean for patients?

Global drug markets have become more dynamic, more digitally enabled, and more internationally connected. New synthetic drugs and novel psychoactive substances can emerge rapidly and spread quickly via online marketplaces. For patients, this means that street supplies are increasingly variable in content, potency, and purity, making consumption riskier and self-report less reliable as a sole source of clinical information.

How can clinicians adapt when they don't know which new substances are in circulation?

Professor Paul Griffiths' research suggests that clinicians do not need entirely new frameworks, as existing models of care remain valid. The key adaptations are increased vigilance, broader clinical assessment, open-minded differential diagnosis, and where possible, toxicological confirmation of self-reported substance use. Staying connected to professional networks and emerging clinical guidance is also valuable.

What is the role of drug monitoring and surveillance in clinical practice?

Drug monitoring systems including wastewater analysis, drug checking services, and digital surveillance can provide early warning of emerging substances entering local drug supplies. For clinicians, this type of intelligence functions as contextual information that can sharpen assessment and inform care planning. 

Does The OAD Clinic screen for novel psychoactive substances?

The OAD Clinic's clinical assessment protocols are designed to capture the full complexity of a patient's substance use history, including less common or novel substances. Where clinical presentation raises questions that standard history-taking cannot resolve, our team considers the use of extended toxicological screening as appropriate to the individual case and clinical context.

About the Research

This article draws on findings from the following peer-reviewed publication:

Griffiths, P., Parry, C., Ambekar, A., et al. (2026): "The Need to Revitalise Drug Use Monitoring to Keep Pace With a More Dynamic, Digitally Enabled and Globally Connected Drug Market", Drug Alcohol Review, volume 45(1):e70029. DOI: 10.1111/dar.70029. E-published 16 September 2025.

About Professor Paul Griffiths

Professor Paul Griffiths is a leading international researcher in the field of drug use, drug policy, and drug monitoring. He is a featured expert contributor at The OAD Clinic, and his work informs the evidence base that underpins our clinical approach to addiction treatment. Read Professor Griffiths' full profile at The OAD Clinic.

Expert Q&A: Professor Griffiths on shifting poly-substance use, public health frameworks and automated data

This Q&A draws on findings from: Griffiths, P., Parry, C., et al. (2026): The Need to Revitalise Drug Use Monitoring to Keep Pace With a More Dynamic, Digitally Enabled and Globally Connected Drug Market, Drug Alcohol Review; volume 45, issue 1: e70029. DOI: 10.1111/dar.70029. E-publication: 16 September 2025.

Question: For clinics operating in regions with shifting poly-substance use, what initial steps or adjustments could be integrated into a clinician’s daily routine so they can adapt patient care plans in real time?

"This is not a simple question, as much of the challenge arises from the speed of change and the increasingly complex patterns of polysubstance use that accompany it. Clinicians may therefore sometimes feel poorly equipped to respond. Reassuringly, however, this greater complexity does not mean that existing models of care or core clinical competencies are no longer valid. Rather, there is a need for clinicians to be both more open-minded and more vigilant, recognising that patients may not always know which substances they have consumed and in responding to both acute and more chronic conditions, what constitutes appropriate care, may be complicated by the co-consumption of multiple substances."

Professor Griffiths

Question: As public health frameworks shift toward using automated data, what can help clinical staff balance these objective data streams with patient self-reporting?

"Clinical staff can best balance automated data with patient self-report by using surveillance data as contextual intelligence rather than as a substitute for clinical judgement. Automated systems can alert clinicians to emerging drug trends and potential responses, but patient self-report remains essential for understanding individual use, context, intent, symptoms and care needs. The most useful approach is to triangulate data, with self-reports, and clinical assessment to support timely, person-centred care. Where possible, toxicological confirmation of self-report data can be helpful; however, in many settings this may not be feasible within an appropriate time frame to inform a clinical response."

Professor Griffiths

About the Author

This article was written and reviewed by Luciana D'Agnone BA, MSc, Director and Editorial Lead at The OAD Clinic. Luciana oversees the clinical content published at The OAD Clinic, ensuring it reflects current evidence, clinical experience, and the values of person-centred addiction care.

1. Griffiths, P., Parry, C., Ambekar, A., Vicknasingam, B., Basutu, A., Myers, B., Bo, A., Dietze, P., Douglas, K., Ezard, N., Fiore, M., Hynes, M, Jones CM, Kent P, Mounteney J, Niaz K, Palczak K, Pascale A, Peacock A, Rychert M., Sturua, L., Zhang, YA (2026).: The Need to Revitalise Drug Use Monitoring to Keep Pace With a More Dynamic, Digitally Enabled and Globally Connected Drug Market, Drug Alcohol Review; volume 45, issue 1: e70029. DOI: 10.1111/dar.70029. E-publication: 16 September 2025.