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 highpotency 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.
