Police Drug Seizures Cannot Solve the Problem of Toxic Drug Supply in North America

In this issue of AJPH, Ray et al. (p. 750) present important findings on the relationships between local area indicators of drug market activity, focusing on the potential unintended consequences of local area drug law enforcement. Finding impacts of seizures on overdoses in subsequent days within local areas highlights the potential for unintended consequences of law enforcement activities on indicators of public health such as overdose.

The unintended consequences of law enforcement activities around drug markets and their impacts on people who use drugs have long been documented in a range of studies.^1,2 This ecological analysis by Ray et al. adds to this literature with an interesting hypothesis around a local area relationship between drug market supply and the tolerance of people who use drugs, long known as a risk factor for opioid overdose (e.g., Dietze et al.³). Ray et al. postulate two mechanisms by which market disruption and the removal of supply could impact tolerance—people who consume drugs may shift supply sources and obtain drugs of unknown quality that they cannot tolerate or they may reduce their use, leading to a reduction in tolerance. They indicate that they do not set out to specifically test these hypotheses, and the limitations of their cross-sectional ecological design precludes such hypothesis testing.

Indeed, the ready availability of high-potency opioids and stimulants in US drug markets⁴ potentially undermines this argument because it is not clear whether the seizures in the study by Ray et al. actually disrupted drug supply or changed drug prices or the quality of available drugs. Previous work on the heroin market in Sydney, Australia, suggests that seizures have little impact on purity or availability in conditions where heroin was readily available,⁵ often termed the heroin “glut” (a period of sustained ready availability of cheap, high-quality heroin),⁶ and this may also apply to current drug markets in Indiana.

There are other potential explanatory mechanisms that may underpin the findings of Ray et al. Previous work has established that local area market disruption can lead to riskier patterns of use such as rushed injection or seeking out more deeply hidden places to use drugs.⁷ These direct impacts observed in relation to street-based drug law enforcement may exacerbate the risks of overdose—for example, more deeply hidden spaces may limit the availability of response.⁷ Alternatively, displacement to different places of drug use may also impact tolerance.³ A fine-grained analysis of the locations of the overdoses in the study by Ray et al. could test whether displacement to riskier locations occurred in response to the seizures in their study. Complimentary studies with people who use drugs in the local areas could also help unpack the explanatory mechanisms of their findings. Furthermore, police presence and operations in drug markets antecedent to seizures may also produce displacement effects, and, so, cataloguing and studying police operations may help unpack the causal paths.

The relationship between drug law enforcement and public health is typically fraught. Performance indicators around street-level drug law enforcement are rarely specified beyond simple metrics such as arrests and seizures, which may not impact drug use and harms such as overdose. Nevertheless, drug supply is fundamentally important to illicit drug-related harms. The Australian heroin “drought,” which occurred after the “glut,”⁶ shows how a major interruption to supply can reduce key indicators of drug harms such as overdose.⁶ However, although law enforcement operations are cited as one possible cause of the Australian heroin drought,⁸ these claims are contested,⁹ and there is currently no indication of any abatement of the toxic illicit drug supply in North America.

In the face of the North American overdose crisis, new approaches and policies around drugs are being trialed that involve partnerships between law enforcement and public health (e.g., Formica et al.¹⁰). Although there are serious concerns with some elements of these approaches,¹¹ and peer-led models may prove superior in the long run,¹² a dialogue between law enforcement and public health on their approach to drug law enforcement in the context of the overdose crisis is at least a step forward to the coordinated drug strategy required to reduce the devastating consequences of current practices in the United States.