Edward Bilsky of the University of New England, left, and Maureen Boyle, chief of Science Policy Branch of the National Institute on Drug Abuse, brief policymakers on opioid overdose epidemic. | AAAS/Craig Poskanzer
Potent neurological forces underscore the challenge facing scientists and policymakers as they work to reverse a continuing climb in opioid overdose deaths in the United States, according to a presentation two opioid experts delivered on 7 June to a bipartisan House caucus.
Maureen Boyle, chief of the Science Policy Branch of the National Institute on Drug Abuse, and Edward Bilsky, a professor of pharmacology and the founding director of the Center for Excellence in Neurosciences at the University of New England, showed how opioids can commandeer the brain’s natural systems that control pain and reward, and trigger a vicious response cycle that can diminish the pain-relieving power of medications, prompt users to reach for increasingly larger quantities of opioids and lead to deadly overdoses.
An estimated 30% of people who try opioids develop an addiction, Boyle said.
“Opioids have both analgesic and rewarding effects and they have these effects through mu opioid receptors and these receptors are expressed in pain terminals in the spinal cord and in areas of the brain that regulate pain but are also expressed in areas that regulate reward and a sense of pleasure,” Boyle said, referring to cells found in a person’s central nervous system that bind to naturally occurring opioid compounds and reduce pain and make people feel much better. “Binding to these opioid receptors activates this reward circuit and basically every substance abuse activates this circuit.”
But repeated use of opioids force the circuits into overdrive, and that exacerbates the damage to a person’s physical and psychological health, said Boyle, pointing to slides of brain scans.
“The overview of what the research tells us is that addiction is a disease that dysregulates brain circuits,” Boyle said. “An opioid addiction has a dysregulation of brain functions, decision making abilities, your ability to control your impulses, dampens your response to your natural pleasures, impacts learning and memory.”
The AAAS Office of Government Relations hosted the well-attended briefing with the support of the Dana Foundation, a private philanthropic organization that promotes brain research and related educational initiatives, and in conjunction with the Congressional Neuroscience Caucus, co-chaired by Reps. Cathy McMorris Rodgers, a Washington state Republican, and Earl Blumenauer, an Oregon Democrat.
“Addiction is a continuum from the very first time you try these things to the point where it starts to become a pattern of behaviors. They start to impact your personal life, your family life until it becomes the sole focus of your life and your life revolves around heroin or prescription opioids,” said Bilsky in an interview before his presentation. “That proves to be very, very challenging.”
To reverse opioid death rates, Bilsky called for comprehensive responses, informed both by the experiences of the nearly 100 million Americans who suffer from chronic pain each year, and those with an opioid use disorder, as well as scientific research and public policy prescriptions.
He cautioned that policy responses must be measured to guard against making it more difficult for those who legitimately suffer from acute or chronic plain to get access to treatment. He also called for early prevention programs and the need to engage those with opioid use disorders and encourage them to share their stories, an approach that can remove the stigma attached to the disorder and prompt others to seek help.
In the United States, 2.5 million people now suffer from an opioid use disorder, said Boyle. The Centers for Disease Control and Prevention reported late last year that 2014 saw a record 28,647 overdose deaths due to the misuse of prescription opioids and heroin.
Opioids are a category of painkillers such as Vicodin, Percocet, OxyContin and the synthetic opioid fentanyl, which authorities found responsible for the death of music legend Prince on 21 April. Fentanyl, prescribed by doctors for cancer treatment, is up to 50 times more potent than heroin and up to 100 times more potent than morphine, according the U.S. Drug Enforcement Agency.
The epidemic’s reach also has setback advances in other health care areas. For example, there was a five-fold increase in babies born with neonatal abstinence syndrome, a withdrawal reaction in newborns of mothers who misuse opioids when pregnant, between 2000 and 2012. There also has been a marked spike in the spread of infectious diseases including HIV and hepatitis C infections across the country.
A “scary statistic,” Boyle cited was a research finding showing that doctors continue to prescribe opioids for 91% of patients who have experienced an overdose. And more than two thirds of those patients are still receiving high doses of opioids from a month to three months after they overdose.
U.S. Health & Human Services Secretary Sylvia Burwell last year proposed a response, calling for a program to change doctors’ opioid prescribing practices, to expand the use of naloxone, a drug used to reverse the effects of an opioid overdoses, and increase patient access to medication assisted treatments for opioid use disorders. The department recently proposed a rule still awaiting approval that would double the number of patients with drug use disorders that doctors can treat.
The National Institute of Drug Abuse has found that increasing access to medication assisted treatment decreases opioid use, deaths related to overdoses, crime and the transmission of diseases, Boyle said, though the approach is not being used enough.
The agency has ongoing research examining the effectiveness of drugs such as methadone, buprenorphine, and naltrexone that are used to wean people off of stronger opioids, as well as research developing alternatives such as vaccines and transcranial magnetic stimulation to treat opioid addictions.
“We are working to produce science based solutions to preventing overdose deaths,” said Boyle.