Stress can lead to an abundance of long-term issues like depression, anxiety, alcoholism, and even drug addiction. Primate research has shown that monkeys with high levels of stress have an increased risk of cocaine addiction.
This same research may provide biological evidence as to why those in lower socioeconomic classes may be more likely to become addicted to drugs. This primate research may also point to projected increases in addiction after the COVID-19 pandemic’s impact on the economy.
A study by Dr. Michael Nader at Wake Forest University looked at the role of social hierarchy in the likelihood of a monkey becoming addicted to cocaine. Nader and his team housed monkeys in groups of four and ranked them from most dominant to most subordinate where the most subordinate monkey would lose in fights against all other monkeys.
Monkeys who were the most subordinate were found to have lower amounts of D2 receptors than dominant monkeys. D2 receptors are proteins in the brain that process dopamine, the neurotransmitter in our brain in charge of happiness. When D2 receptors are in low supply, the individual is likely under stress.
“The subordinate male monkeys were more vulnerable to cocaine abuse,” Dr. Nader said. “This shows how social variables can impact vulnerability.”
Low D2 levels seem to correlate to higher cocaine use. These monkeys were found to not only self-administer more cocaine than dominant monkeys but also have more difficulties recovering from the addiction. This same research can be applied to humans.
“For the most part, humans and monkeys share most hormone profiles,” said Dr. Nader. D2 and Dopamine is a hormone profile humans and monkeys have in common.
A study by Dr. Corinde Wiers published in Neuroscience Letters, found that the majority of cocaine abusers had much lower levels of D2 receptors compared to non-cocaine users. This research mirrored what was found in monkeys.
The study also found that the majority of those who used cocaine were ranked in a lower socioeconomic status than those who did not use cocaine.
“There’s higher D2 receptor availability in those in the higher social status and that is the exact same correlation in humans,” said Ben Johnson, graduate assistant in Dr. Nader’s lab.
Wiers’ study found a direct relationship between D2 levels and socioeconomic class in humans. Socioeconomic class was determined by occupation and level of education.
The stress of worrying about income, wealth, education, and discrimination can cause chronic stress for those in the lower class. It’s harder to obtain resources and they don’t’ have much control over their environment. As a result, the amount of dopamine intake?? by the brain decreases. This could lead people to resort to use of cocaine or other drugs to relieve that stress.
Besides D2 receptors, there are other stressors we share with monkeys that may correlate to an increase in drug abuse.
“Other things within nonhuman primates that correlate besides social rank and socioeconomic status are stressors, reproductive health, immune health, and allocation of resources which is another level of vulnerability and stress,” Johnson said. “There is a higher prevalence of substance abuse in lower socioeconomic status for a lot of those reasons.”
Unfortunately, changing social status isn’t an easy fix for those trying to recover from drug addiction. Even worse is that people across the nation are experiencing more socioeconomic stress than ever before.
In the past few weeks, there’s been a large increase of financial stress affecting Americans due to the rise of Covid-19. Many individuals have already been laid off due to business closures.
Economists at the Federal Reserve’s St. Louis district estimate a drop in total U.S. employment of 47 million. That’s equivalent to a 32 percent unemployment rate.
With such a large amount of newly unemployed people worried about not only keeping their family healthy but also financially stable, we can speculate many individuals to resort to drug use to calm their stress.
According to the Center of Disease Control, the large amount of stress this pandemic has caused can lead to increased use of alcohol, tobacco, and other drugs. People under safe-at-home orders may feel the need to calm their stress through the use of substances. Even after the pandemic is over, individuals of lower socioeconomic classes may form an addiction that’s hard to recover from.
Both Ben and Nina Norman, another graduate assistant in Dr. Nader’s lab, agreed that the stress caused from COVID-19 may cause many Americans to form a substance addiction of some kind even post-pandemic.
“I think we will definitely see some impact in addiction from COVID-19,” said Nina. “Due to the various stay at home orders, people will be spending more time in the home which for some causes an increases in stress. I’m sure we will see a lot of papers surrounding COVID-19 in the next few months or years.”
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