LA JOLLA, Calif. — Could deep brain stimulation be used to prevent relapse in drug addicts? A new study finds that the treatment successfully helped rats battle heroin addiction.
In a study conducted by scientists at The Scripps Research Institute, the rats showed their need for heroin was greatly reduced when deep brain stimulation was used. When the rats were subjected to electric pulses, they stopped pulling a lever that they’d discovered injects them with heroin.
The treatment is a relatively weak electrical surge to the subthalamic nucleus through implanted electrodes.
“It has been very difficult to reduce heroin-seeking and taking in an animal model because heroin is such an addictive drug, but the results here are very impressive,” the study’s principal investigator Olivier George, associate professor in The Scripps Research Institute Committee on the Neurobiology of Addictive Disorders, said in a release. George also states that these type of findings are exactly what scientists need to move forward with “testing [the] strategy in humans.”
The results are making scientists look at neurocircuitry in a different manner, especially when it comes to heroin addiction. This treatment is already administered to patients with symptoms of Parkinson’s and “essential tremor.”
The part of the brain that is stimulated is still a relatively unknown landscape to scientist, but they are making progress as this test proves the subthalamic nucleus causes unusual muscle activity of movement disorders and also uncontrollable actions. In Parkinson’s patients, stimulation helps reduce gambling and shopping addiction.
The practice was even approved by the FDA in 2009 for extreme cases of obsessive-compulsive disorder. Cocaine addiction has even been studied, in rats, and stimulation can reduce motivation to digest the drug.
In the heroin study, rats are allowed to self-administer the drug for twelve hours a day but only for half the day, via a lever. This happens for a two week period. George compares the test to “a human drug user who goes into rehab for two weeks, and then comes back into the real world where he has access to the drug, and starts taking more and more again.”
In the study, only the rats who had received no stimulation continued their extreme addiction to heroin after the rehab period. The rats who received the treatment still administered the drug but in smaller, more stable increments.
However, one unexpected finding was that when the researchers stopped administering the stimulation the rats returned to consuming addictive levels of heroin. “It was really like an on-off switch,” George said. “Then two days later we turned it on again and their intake came back down.”
All in all, the stimulation worked in the rats and the researchers believe that is can be something used as an alternative to treat heroin addiction. Carrie L. Wade, who was a postdoctoral research assistant during the study, believes that “deep brain stimulation can be a useful non-drug intervention for treatment of addiction,” according to the release.
It should be noted that the stimulation administered was in much smaller doses than in other studies, which is why George believe they found such impressive results. “We think the low intensity of stimulation will affect only the emotional, motivational part of the subthalamic nucleus and not the part that’s involved in controlling muscle movements, “ he adds.
The study was published recently as an advance online paper in the journal Neuropsychopharmacology. It was funded by the National Institute on Drug Abuse and the Pearson Center for Alcoholism and Addiction Research