Researchers examined cases of adverse drug reactions in people trying to quit smoking. They say people taking Chantix were more likely to become depressed and even suicidal than smokers using other methods, such as the patch.
The study contradicts a recent FDA report which said Chantix has no more risk than other drugs aimed at helping smokers quit. Pfizer, the maker of Chantix, says the study does not prove a cause and effect relationship. The FDA has ordered Pfizer to conduct a trial looking into the drug's safety.