Why genetic testing is a tool — not a solution — to the opioid epidemic
The Food and Drug Administration (FDA) recently announced approval of AvertD, the first genetic test to help identify elevated risk for developing opioid use disorder — welcome news for the 3 million Americans whose lives and loved ones have been negatively impacted by opioids.
Opioid use disorder is a pattern of opioid misuse that causes significant impairment and distress. The disorder frequently leads to overdose-related deaths, which nearly quadrupled between 2010 and 2021. Even if you have never faced a problem with opioids yourself, a recent survey found that three in 10 adults in the U.S. know someone who has been affected by opioid use disorder.
Interventions to quell this epidemic are urgently needed. But a genetic test to identify risk of opioid use disorder fails to address the burden among the most marginalized people — and may cause more harm than benefit.
As genetic anthropologists and public health professionals who have been personally impacted by substance use disorders, we have seen firsthand how structural factors such as poverty, rural despair and criminalization can contribute to substance misuse. We argue that any approach to identifying risk for the disorder must meaningfully address these structural factors. Relying on genetic testing to prevent future opioid use disorder rather than addressing the mounting public health emergency of the current opioid crisis will be a medical and public health failure.
Like many complex traits, this disorder has a genetic component, but the specific relevant alleles, the strength of their contributions and the biological pathways through which they act are still largely unknown. Reducing a person’s risk to only 15 genetic variants is overly reductive and unlikely to be effective when studies of millions of variants have not been able to accurately predict the disorder.
Moreover, genes do not act in a vacuum, but interact with complex networks of social, economic and psychological factors, especially for behavioral traits like substance use disorder. Economic hardship, housing instability, trauma, lack of social support and systematic disinvestment in marginalized communities are all important drivers of opioid use disorder. A genetic test result may be effectively meaningless without considering this context.
We and other geneticists are also concerned that the test may increase existing racial and ethnic disparities in opioid prescriptions. This is because the 15 variants used in the test have large frequency differences across populations. When tested in a larger dataset, these variants were found to accurately predict the race of a patient, but when participant ancestry was balanced, it could not predict opioid use disorder “better than a coin flip.”
Since the new test was validated on a dataset of 94 percent white patients, it may help reduce risk in white populations, but may misclassify risk for minoritized people, especially those with mixed ancestries.
While the FDA cautions against using the AvertD test alone, there is little guidance on how clinicians should incorporate the test into clinical evaluations. This is troubling in a medical landscape that is biased against racially marginalized communities.
For example, a nationwide study found that Black patients were significantly less likely to receive opioid prescriptions for pain, and received lower dosages when opiates were prescribed. While a genetic test could theoretically reduce clinician bias, it could also introduce additional barriers due to the expense — the test is currently $199 — and could potentially limit access to pain medication for those most in need.
Genetic testing for risk also fails to address existing disparities in treatment and outcomes. Although white people are most likely to experience opioid use disorder, overdose rates are disproportionately increasing in Black populations. This is partially due to inequitable access to safe and effective medicines like Naloxone, which can prevent overdose deaths. A 2021 study found that women, Black adults, people who were unemployed, or those living in nonmetropolitan areas were significantly less likely to access opioid use disorder medications. Using a biased genetic screener could exacerbate these disparities.
Instead of focusing on the risk for developing opioid use disorder, we should invest in models that offer treatment, service provision and decriminalization to help the most impacted communities. We urgently need harm reduction strategies that meet people where they are. Naloxone should be made widely available, along with clean syringe services and fentanyl testing strips to make drug use safer. Mobile clinics could connect patients to safe and stigma-free substance use disorder treatment. These are important programs especially for those who lack access to medical care.
While the new screening test may be well intentioned, it should also be considered within the larger historical context of our regulatory agencies’ failures to ensure efficacy and safety of opioid use in the past. With a medical system that is already built on a history of racism and sexism, we need structural change and emphasis on existing evidence-based harm reduction strategies — not deterministic genetic tests — to address the opioid crisis.
Sam Streuli is a Public Voices Fellow of the OpEd Project and AcademyHealth. They are a writer and researcher in public health whose work is focused on health equity and justice.
CJ Valasek is a senior research associate in the School of Medicine at the University of California San Diego. Their research focuses on mental health and substance use services.
Cassidy Tomlinson is a Ph.D. student at the University of California San Diego. She is a genetic anthropologist whose current research focuses on the epigenetics of substance use.
Amy Non is a professor of anthropology at University of California San Diego. Her research focuses on genetic and cultural contributors to racial and social health disparities.
Any opinions expressed here are solely their own and do not represent those of their employers.
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