A treatment that uses targeted magnetic pulses to the brain may reduce craving and substance use in people addicted to cocaine, a small study suggests.

The researchers found the treatment helped 70 percent of study participants to lose their cravings for cocaine. Some have stayed free of the drug for a year, NBC News reports.

The findings appear in the journal European Neuropsychopharmacology.

“They don’t crave cocaine any more. They get their lives back,” said study co-author Dr. Antonello Bonci of the National Institute on Drug Abuse. “They say it feels like a black cloud has been removed from their head.”

In an earlier study in cocaine-addicted rats, Bonci found the rodents had very low levels of activity in the prefrontal cortex of the brain, which is involved in decision-making and impulse control.

When the rats’ brains were stimulated, they immediately lost interest in cocaine, he said. The technique used in the rats, called optogenetics, is too invasive to use in humans. The researchers decided to try a non-invasive technique called transcranial magnetic stimulation (TMS) in a human study.

TMS, involves placing a large electromagnetic coil over the head. It was approved by the U.S. Food and Drug Administration to treat depression in 2008.

The new study included 32 patients, who on average used cocaine for 10 years, four times a week. Half were treated with TMS. Patients knew whether they were receiving TMS treatment or a placebo, which may have influenced the results, Bonci noted.

After three months, 11 of the 16 patients treated with TMS were no longer using cocaine. Among the 16 who received the placebo treatment, only three did not return to cocaine use. The 16 patients who had not received TMS were offered the treatment. Ten accepted, and seven of them stopped using cocaine.