Addiction researchers are explorers of and caregivers to a hidden land of human suffering.
Society tends to think of the principal drug-abuse challenge as prevention rather than treatment of those already addicted to drugs. And addicts tend to keep to themselves, their problems shrouded by fear of legal sanction and social stigma.
For scientists willing to carefully reach out, addiction research offers a rare chance to explore the dynamics of how changes in the brain become changes in perception and behavior, and an invaluable opportunity to find new ways to pull lives back from the brink.
Hopkins addiction researcher Sharon Walsh, an assistant professor of psychiatry, recently received a Presidential Early Career Award for Scientists and Engineers, the nation's highest award for young researchers. She will get up to $500,000 over five years to further her research in cocaine and opioid drug abuse, withdrawal and treatment.
"She's done a wide array of unique and remarkably comprehensive experiments related to medications for drug abuse," says George Bigelow, professor of behavioral biology and psychiatry and a colleague of Walsh's.
Bigelow praises Walsh's recent work with LAAM and buprenorphine, two new compounds used to treat patients addicted to opiate drugs like heroin. "Sharon's work with these drugs provided answers to important questions about how to safely and effectively use them as treatments for addiction," he says.
Walsh, who receives much of her funding from the National Institute on Drug Abuse, recently began a new project to comprehensively describe the effects of chronic cocaine use and withdrawal in human subjects.
Scientists have debated for years whether cocaine creates a withdrawal syndrome--sometimes also known as physical dependence- -dramatic changes in brain function and other vital systems that become detrimental when exposure to the drug stops.
"Psychologically, cocaine is very addictive; there's no debating that," Walsh says. "It provides the reward, the 'high,' necessary to create the repetitive behavior pattern."
However, not all drugs that are psychologically addictive also create physical dependence.
Whether or not cocaine causes physical dependence is still unclear, and Walsh is hoping her new study will help provide some answers.
Incorporated into her studies is a plan for testing a new treatment for cocaine addiction: a group of compounds called kappa-agonists.
"Cocaine acts on the dopamine system, a chemical messaging system in the brain," Walsh says. "A number of drugs can block access to the dopamine system. These are drugs used as antipsychotic agents. But for long-term use in addiction treatment, they have some potentially serious side effects."
The kappa-agonists, developed years ago as an alternative to pain-relief agents like morphine, act on a different chemical messaging system in the brain. That system can in turn have effects on dopamine levels and use in the brain.
"That means they could potentially provide us with a way of getting at the same outcome--blocking cocaine's effects--without incurring the same risks," Walsh says.
"Unlike some of the other addictive drugs, we currently have no FDA-approved treatment for cocaine abuse," Walsh adds. "That makes finding something that can help us fight this problem a big priority."
Although there is nothing they can do to force the volunteers who participate in their studies to get treatment, Walsh and her colleagues make sure all are given the proper referrals and the opportunity to get professional help in ending their addiction.
"It's a tremendous commitment for many of our patients, and we do everything we can to encourage them to make it," she notes. "At the same time, though, the resources available for treatment keep shrinking, which can make it an even greater commitment. We have, at a guess, probably 10 percent of the number of treatment slots for IV drug users that we need in the city of Baltimore."
That can leave someone who wants help quitting on hold for a few months as they continue to be exposed to the health and safety risks of drug abuse, Walsh notes.