British researchers say they found no evidence that the stop-smoking drug varenicline leads to depression or increased suicide risk, HealthDay News reported Oct. 2.

The drug, sold as Chantix, has been the target of complaints and lawsuits alleging that some users experience psychotic side-effects, and the U.S. Food and Drug Administration recently ordered that a warning to that effect be placed on product packaging.

However, a new review of medical records of 80,660 people prescribed Chantix, bupropion (Zyban) or nicotine-replacement products for smoking cessation found no evidence that varenicline or bupropion increased the risk of self-harm, suicidality or depression. Some risk could exist, they acknowledged, but further research would be required to determine if that is the case.

The findings were published online on Oct. 1 in the British Medical Journal.