LOS ANGELES, April 27 (UPI) -- Adding exercise to methamphetamine addiction counseling leads to changes in the brain researchers say could help people trying to beat a habit, according to a new study.
Researchers at the University of California Los Angeles report exercise helps the brain add new dopamine receptors, which they said lowers desire for methamphetamine and makes it easier to recover from addiction.
Methamphetamine use creates a rush of dopamine, a substance that naturally provides sensations of pleasure and satisfaction but also causes the drug's approximately six-hour high, which results in a reduction in the number of dopamine receptors as the drug is used more and for longer periods of time.
Although the receptors can recover, how much depends on how long a person has used methamphetamines, with chronic use potentially causing longer-lasting problems with judgment and self-control -- which makes abstaining from the drug even more difficult for longtime users.
"We know that deficits in the striatal dopamine system are hallmark features of substance-use disorders and are caused by molecular adaptions to repeated drug exposure and, likely, also reflect a genetic predisposition," Dr. Edythe London, a professor of psychiatry and molecular and medical pharmacology at UCLA, said in a press release.
For the study, published in the journal Neuropsychopharmacology, researchers recruited 19 people, 10 of whom were asked to walk or jog on a treadmill three times a week for an hour and to do resistance training for eight weeks, while the other nine were given health education training but not asked to exercise.
Before and after the eight-week period, participants were given PET scans to determine the number of dopamine receptors in the striatum, a part of the brain critical to the organ's reward system.
At the start of the study, there was no great difference in number of receptors between the two groups, at the end of the study, exercising participants had a 15 percent increase in receptors, while the education-only group was just 4 percent.
While more studies are needed to determine how this knowledge can be used with patients, researchers are hopeful it could help people with addictions and possibly those with some neuropsychiatric disorders.
"Although this is a small study, it's a very encouraging finding," London said. "The results demonstrate that methamphetamine-associated damages to the dopamine system of the brain are reversible in human subjects, and that recovery of the dopamine system after chronic drug use can be facilitated with exercise training."