Addicts’ brains focus of research at UAMS
Posted on Monday, September 29, 2008
A heroin addict uses another person’s needle to inject the drug into his bloodstream for the same reason a cocaine addict commits armed robbery or an alcoholic skips work to go to a bar, experts say.
Getting the next high matters more to addicts than future consequences.
A recent study found nonaddicts think of the future as an average of 4. 7 years away. For heroin addicts, it’s just nine days, experts say.
“They have a very different view of time,” said Warren K. Bickel, director of the Center for Addiction Research at the University of Arkansas for Medical Sciences. “Any consequence of that risk-taking is going to be beyond that nine-day period in which they’re contemplating their future, so for all... purposes, there is no risk.”
Bickel and his research team were awarded a five-year, $ 2. 7 million grant to study how addicts’ brains work and whether strengthening the part of the brain that controls future thinking helps improve treatment outcomes.
It’s Bickel’s fourth grant from the National Institutes of Health’s National Institute on Drug Abuse.
Located at the front of the brain between the eyes, the prefrontal cortex controls executive function, which affects the ability to plan and commit to future actions and goals, said Bickel, who has studied addiction for 25 years.
MRIs of addicts’ brains show that when people are focused on fulfilling their addiction, there’s more activity in the region toward the back, the area of the brain that seeks immediate gratification, and little activity in the prefrontal cortex, he said.
“We’re starting to understand addiction not as a single-process phenomenon, but a dual-process phenomenon,” Bickel said. “There’s increased activity in the part of the brain that says, ‘I want it now,’ and decreased activity in the part of the brain that says, ‘I’ll have it later. ’”
Like muscles, the strength of the prefrontal cortex depends on how often it’s used. Bickel said his goal is to find a way to increase the strength and utilization of executive function for addicts.
Over the next five years, UAMS researchers will work with about 360 people who are addicted to the stimulants cocaine or methamphetamine. Participants will do exercises to get them to use their prefrontal cortex, Bickel said. Researchers will test their memory, how well they can develop alternative plans, how they prepare for a complex task, and how well they can restrain themselves from potentially harmful behaviors.
Such techniques have already proved helpful in strengthening executive function in patients with schizophrenia or traumatic brain injuries, he said.
If it works, Bickel said, it could lead to new ways of approaching treatment and teaching drug-abuse prevention. Instead of teaching youths to say no to drugs, it could be more effective to get them to exercise their prefrontal cortex so they think more about long-term consequences, he said.
Bickel said he’s working with a team of nine researchers at UAMS, including Jennifer Kleiner, an assistant professor who specializes in neuropsychology, Alan Budney, a professor of psychiatry, and Richard Yi, an assistant professor of psychiatry.
The team is also collaborating with A. David Redish, an associate professor who specializes in theoretical neuroscience with the University of Minnesota’s Department of Neuroscience.
For the project, Redish is developing computer models that show how an addict’s brain processes decisions and responds to treatments.
Just as any number of things can cause a car to break down, any number of underlying problems can lead to addiction, Redish said. That’s why people respond differently to treatments.
The goal is to find a clinical test that could identify who will benefit most from which treatments.
By partnering with Bickel and his team, Redish said he’ll be able to test theories in the clinical setting.
Bickel said the research is being done in conjunction with Recovery Centers of Arkansas, which offers inpatient and outpatient substance-abuse treatment, as well as a “chemicalfree” apartment facility in Little Rock to help addicts transition after treatment.
Carole Baxter is executive director of Recovery Centers of Arkansas and has worked in substance-abuse treatment in Arkansas for 34 years. She said Bickel’s research is exciting because treatment professionals try to get addicts to think about consequences of their actions.
Alcoholics Anonymous, for example, encourages people to “play the tape all the way through,” meaning they should think about what will happen if they take a drink and how it will affect their lives and loved ones.
“Addicts see nothing past ‘ I get the next high, ’” Baxter said. “They don’t see: ‘ I get the next high, I’m high for a while then I lose my job or my family deserts me, or I violated my parole, and I spend 10 years in prison.’ They don’t go through all those things.”
Baxter said Bickel’s research provides a “dose of hope” for people entering treatment, who often feel helpless and hopeless.
“Knowing that there is someone out there looking for a better treatment or even a cure can make all the difference,” she said.
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