During Meth Withdrawal, Just a Little Exercise Helps Prevent Relapse
The quantity of exercise involved did not seem to make a difference—even a very brief workout was effective at helping to prevent the methamphetamine-experienced rats from relapsing during withdrawal.
Another interesting finding was that the exercise affected neurons that had not been previously linked to methamphetamine withdrawal. This suggests possible new targets and pathways for drug therapies that could help methamphetamine users stay on the path to recovery during the difficult withdrawal process.
Previous Study Shows Exercise Lessens Methamphetamine-Seeking
A previous study by associate professor Chitra Mandyam, senior author of the new study, found that running lessened the amount of methamphetamine that drug-experienced rats chose to consume before feeling satisfied.
During that study, Mandyam and her research team found that both running and methamphetamine triggered the brain’s reward centers. Apparently, getting signals from both running and methamphetamine use meant that the rats did not need to consume as much of the drug in order to achieve the same level of reward stimulation in their brains.
Even a Little Bit of Exercise Helped Reduce Drug-Seeking During Withdrawal
During the latest study, two groups of methamphetamine-experienced rats undergoing withdrawal were able to press a lever requesting a dose of methamphetamine whenever they wanted to. In addition, one group of rats was given access to a running wheel.
Even when given access to a wheel, the rats experiencing withdrawal chose to run less than rats that had never been exposed to methamphetamine. Nevertheless, even a minimal amount of time spent on the wheel affected the amount of methamphetamine-seeking displayed by the withdrawing rats.
Similarities to Other Drugs Discovered
Previous research has found similar results for rats experiencing nicotine withdrawal and cocaine withdrawal. During those studies, rats were also less likely to press a lever requesting a dose of the drug if they were given access to a running wheel.
In addition, the researchers saw changes in the brain that had previously been associated with opiate drugs such as heroin. Specifically, they saw that methamphetamine-dependent rats that ran on a wheel had fewer dopamine neurons in the periaqueductal gray (PAG) region of the brain. This change in a brain area associated with pain sensing has not been previously observed during withdrawal from a stimulant drug.
More research is needed to understand how this part of the brain works with other areas of the brain during addiction and withdrawal, but the Scripps team hopes that explaining this connection will shed new light on the brain processes that drive relapse during withdrawal.
An Uphill Battle
Methamphetamine has one of the worst rates of drug relapse of any highly addictive illegal drug. A 2012 study from Australia estimated that even after entering a rehabilitation program, only 20 percent of methamphetamine users remained clean one year later and only 12 percent remained clean three years later.
If the results of this new study translate to humans, it could help to reduce methamphetamine relapse in both the short term and the long term. Getting patients in recovery to engage in even a small amount of physical exercise could help them stay on course through the difficult process of withdrawal, while a more thorough understanding of the chemistry of relapse could help scientists to improve the odds of long-term recovery.