According to a new report, the anti-depressant medicine bupropion (Zyban) tripled quit rates for women and formerly depressed smokers when compared to control groups whose members took a placebo (sugar pill). Findings from a clinical trial were recently published in Nicotine and Tobacco Research (Vol. 5, No. 1: 99-109), and are the first to show high success rates for women and people with a history of depression.

After one year, approximately 26% of the women smokers who used bupropion SR (sustained release) during the eight-week study were still tobacco free, compared with 8.5% of the placebo group. Among formerly depressed smokers, about 29% of the bupropion group members were still non-smokers one year later, compared with 8% of the placebo group.

This encouraging news about quitting smoking comes a few months after research showed that personalized counseling through a telephone quitline can boost success rates, too.

Lead author Stevens Smith, PhD, of the Center for Tobacco Research and Intervention (CTRI) at the University of Wisconsin Medical School, said no one knows exactly how bupropion works in the brain to lift depression, the original use for the drug (sold under the brand name Wellbutrin). For quitters, "the theory is that bupropion eases intense negative moods, expressed as depression and irritability."

"Another advantage is that people tend not to gain as much weight," he added.

Previous research suggested that women and formerly depressed people who quit smoking feel more intense withdrawal symptoms and bad moods for a longer period of time than other quitters.

For about one third of the people who quit smoking, Smith said withdrawal symptoms seem to get worse over time until they relapse. "By about three weeks, they crash and burn," he said.

The marketers of Zyban, GlaxoSmithKline, funded the original clinical trial, which was designed and directed by CTRI researchers. It included 893 people, randomized into four groups. Two groups were treated for eight weeks with bupropion SR tablets (one group also used nicotine patches; the other placebo patches). Two groups received placebo tablets (again one with nicotine patches, one with placebo patches). The patch did not significantly improve quit rates for either group.

Results were first published in 1999 and showed bupropion helped about twice as many smokers quit, when compared with a placebo or a nicotine replacement patch. The new report sifts the data to look at two subgroups with a high risk for relapse.

Quit rates have been about 10-15% lower for women than men, according to Tom Glynn, director of science and trends for the American Cancer Society. So, research about which methods work best for women is important progress.

Glynn said this is the first study to provide clear evidence that women and people with depressive symptoms also can quit successfully.

Both Glynn and lead author Smith are quick to point out that other factors are critical in order for bupropion to work. "I describe this as an effortful process. A lot of people want a magic pill. Zyban is not a magic pill," said Smith. He listed a few other elements quitters may need including:

Study participants had brief counseling sessions weekly and brought in their pill bottles so researchers could count any unused medication. The close supervision ensured that they used the full course of pills and patches — something that doesn't happen enough in the real world, according to Glynn.

"The number one problem with cessation now is compliance. The base problem behind relapse is when people don't continue with their treatment plan, or don't follow it completely," he said.

Quit rates for people using both the pill and the patch were not significantly better than for bupropion alone, but the authors noted they were good enough to deserve further study, especially among women and the formerly depressed. Smith explained why the patch alone might not help the portion of smokers who reach for a cigarette to manage moods or stress.

"The nicotine patch…delivers a steady amount equal to about 60%-70% of the nicotine a person would get from smoking one pack a day. Often, this is not enough when stress comes up suddenly at work, or people come home to family problems."

"We don't have anything that even comes close to cigarettes for nicotine delivery. It only takes six to seven seconds for smokers to feel a rush," noted Smith. But for a quick fix to get past a craving, Smith said nicotine lozenges, nasal sprays, or puffers can help -- as can the coping skills people have practiced.

Smith emphasized that the encouraging results seen with bupropion must be reproduced before they are fully accepted. He noted that studies are testing two other anti-depressants for smoking cessation: nortriptyline and clonidine, and he welcomed every aid smokers can use against tobacco.

"So many people believe it's just a matter of will power, but it's a disease: addiction to nicotine," said Smith. "Cigarettes are simply a nicotine delivery system, a very dirty nicotine delivery system with devastating effects on the lungs, heart, and other parts of the human body."