Flushing out lockdown trends

Wastewater analysis presented at an Autumn meeting of the American Chemical Society (ACS) paints a picture of how people’s drug use habits were changed by the lockdown.

The team identified a spike in the consumption of easily abused prescription opioids and anti-anxiety sedatives between March and June 2020, while some illicit drug use plummeted.

Previously, Bikram Subedi and his research group used residues in wastewater to study illicit drug consumption in rural communities. With the onset of COVID-19 restrictions, the team turned to wastewater again. “We hypothesized that some of the drug profiles would be different, and personal drug use behaviour would be altered due to isolation, loss of jobs and loss of life,” says Subedi, who is the principal investigator on the project.

By June 2020, about 40% of adults in the US were struggling with mental health, and 13% of those had started or increased their substance use, according to survey results published in an August 2020 paper by another team. So, to get an idea of community-wide habits and anxiety levels at the start of the pandemic, Subedi’s team at Murray State University used wastewater epidemiology. They calculated per capita consumption for a diverse set of drugs based on their presence in sewage entering treatment plants. With this technique, the researchers say they developed comprehensive and nearly real-time patterns of prescription and illicit drug use, which are deemed important to public health authorities, law enforcement and other agencies.

The researchers collected raw sewage samples from treatment facilities in two towns in western Kentucky and northwest Tennessee, says Alexander Montgomery, a graduate student. Back in the lab, they measured the levels of easily abused prescription medications, illicit drugs and their metabolites. As Montgomery explains, the team took extra precautions with these samples because no one knew if SARS-CoV-2 could survive in wastewater.

Their results showed that consumption of hydrocodone — one of the most abused prescription opioids — spiked by 72% from March to June 2020. The researchers suggest the change was because people had easier access to doctors as they switched to telemedicine appointments. Conversely, the use of illicit stimulants dropped by 16% for methamphetamine and 40% for cocaine. The researchers suggest that travel restrictions limited interstate and international trafficking of these drugs. “Our results match with all of the sources that we could find pertaining to other drug estimations in the community,” says Montgomery, including declines in city and state police methamphetamine and cocaine seizures. And now, even more, recent data released by the CDC show that nationwide, drug overdose deaths increased by nearly 30% from the prior year with the majority caused by opioid overdoses. Overdose deaths from fentanyl-laced illegal stimulants also increased in 2020.

At the same time, the prevalence of benzodiazepines — anxiety-related sedatives — was elevated by nearly 30% and antidepressants increased by 40%. In a related project that
is also being presented by Subedi’s team, they examined the same wastewater samples for isoprostanes — hormones that indicate oxidative stress and anxiety — and found their levels rose significantly. “That tells us as people’s anxiety levels increased, the levels of prescription drug consumption also increased,” Subedi says, aligning with additional interventions recommended by health professionals to treat elevated mental health issues.

“The trends that we are reporting are only for the first four months of the early COVID-19 pandemic, and they may not be true for an extended period of time,” Subedi says.

Although the pandemic is now receding in some parts of the world, the team continues monthly wastewater sampling. Subedi notes that monitoring the trends of drug use and community-level anxiety post-pandemic will help explain the overall effects that the COVID-19 measures have had on people’s lives.