The antidepressant mirtazapine (Remeron) can help reduce methamphetamine dependence, a new study suggests. Researchers found people dependent on methamphetamine who took the antidepressant every day for 12 weeks were much less dependent on the drug after three months compared with those who took a placebo, according to the San Francisco Chronicle.

Previous studies of potential treatments for methamphetamine dependence have not yielded promising results, the article notes. Addiction to methamphetamine can be very difficult to treat.

“This is exciting to see because with methamphetamine, virtually everything we’ve tried hasn’t worked. There have been quite a few bombs pharmacologically,” Stanford University psychiatry professor Keith Humphreys told the newspaper. “At the same time, those earlier experiences have taught me to be cautious now.”

The study included 60 men who were addicted to methamphetamine. Half were given a daily dose of the antidepressant, and half were given a placebo. All of the men received counseling. They were given weekly urine tests to check for methamphetamine. Among those who took the antidepressant, the rate of positive urine tests fell from 73 percent to 44 percent over the course of the study. Among men who took the placebo, positive tests fell from 67 percent to 63 percent, the researchers reported in the Archives of General Psychiatry.

The study was conducted by researchers at the San Francisco Department of Public Health, which is especially interested in methamphetamine addiction because it is closely connected with exposure to HIV, the article notes. Methamphetamine lowers inhibitions and increases feelings of invulnerability, which can lead to risky sexual behaviors and can increase the risk of HIV infection, said lead researcher Dr. Grant Colfax.

He noted the study found participants who took mirtazapine reported fewer risky sexual behaviors than their counterparts who took a placebo drug.