The preliminary trials, which were conducted on mice, showed that the drug is able to erase the unconscious memories that underlie addiction.
Environmental cues play a huge role in whether or not someone will relapse into their addictive habits. These cues include the people, places, sights, and sounds that an addict experiences before abusing their drug of choice. When an addict experiences these cues, their cravings become much more poignant and harder to control.
The study, which was led by Hitoshi Morikawa, attempted to erase the connections that an addict has between environmental cues and their drug abuse. By eliminating the triggers that lead to relapse, they hope that it will become easier for former addicts to stay clean. The drug that they used to eliminate these connections is called isradipine, which is commonly used to treat high blood pressure.
Addicted rats
For the purposes of the study, researchers trained rats to associate either a black or white room with the use of a drug. Rats that developed an addiction would almost always prefer the room that correlated to their drug.
After some time, researchers gave the addicted rats a dose of isradipine before they made their choice of which room to go to. While the rats chose the room that they associated the addiction with on that day, the choices became more varied on subsequent days. They no longer showed a preference for which room they wanted to enter.
“The isradipine erased memories that led them to associate a certain room with cocaine or alcohol,” said Morikawa.
The science behind addiction and what it does to the brain is fascinating. Scientists believe that addictive drugs rewire the brain’s concept of reward learning, which makes memories of drug-related cues more powerful. Isradipine, and other hypertensive drugs, block a particular ion channel in the brain, which reverses the rewiring process and disassociates memories of environmental cues with drug abuse.
Morikawa and his team believe that isradipine can help support addicts who want to quit. “Addicts show up to the rehab center already addicted… [They] want to quit, but their brains are already conditioned. This drug might help the addicted brain become de-addicted,” he said.
Since isradipine is already approved by the FDA, clinical trials may be able to start much more quickly than with other drugs. Caution must be exercised, though. Because isradipine is designed to lower a person’s blood pressure, it might be necessary to pair it with other medications to keep it at safe levels. Proper usage and additional supplements will need to be explored before it can be made ready for the public.
The full study has been published in Molecular Psychiatry.