When it comes to quitting smoking, it pays to be prepared. Smokers who started taking the drug bupropion four weeks before quitting, instead of the standard single week, had a much better success rate in a randomized trial.

Bupropion (Wellbutrin, Zyban) is an antidepressant that is sometimes prescribed as an anti-smoking aid. It lessens nicotine cravings and withdrawal symptoms, though the exact mechanism of how it does this is not yet known.

During the four weeks before their quit date, the bupropion group reported smoking less and having fewer cravings.

Anecdotal evidence suggested that people who were taking bupropion as an antidepressant cut down smoking even though they had no intention of doing so. So University of Buffalo psychologist, Larry Hawk, set up a new trial to see if longer exposure to bupropion would do the same because quitting smoking at any age is a major health bonus.

Half of the smokers in the trial took placebo for three weeks followed by a week of bupropion in the four weeks leading up to their quit date. The other half took bupropion for the full four weeks. All of the subjects also received state-of-the-art smoking cessation counseling and continued to take bupropion for seven weeks after their quit date.

“One of the things I love about this type of study is that everybody gets a good treatment,” Hawk said in a statement. “Our control group is getting standard effective therapy.”

All the participants had been smoking at least 15 cigarettes a day before the study. During the four weeks before their quit date, the bupropion group reported smoking less and having fewer cravings. More importantly, at the end of the study, the biochemically verified quit rate (four consecutive weeks without smoking) was 53% in the extended bupropion group compared to only 31% in the standard/control group.

“These studies are exciting because they suggest that we might be able to nearly double success rates using the same medications we already have. There's the potential to help a lot of people live longer, happier lives,” Hawk said.

The study appears in Nicotine & Tobacco Research.