Researchers who reviewed 511 previously published studies on smoking cessation found that two-thirds to three-quarters of individuals who quit did so aided only by their own willpower, not nicotine-replacement therapy or other drugs.

The Daily Mail reported Feb. 9 that Simon Chapman of Australia's Sydney University and colleagues also found that studies that found positive outcomes from drug therapy for nicotine addiction were more than twice as likely to have been funded by the pharmaceutical industry.

Chapman said that most smokers who quit said kicking the habit was easier than they expected, and he accused governments of medicalizing the process and making smoking seem especially difficult to quit.

'Next time you hear the message that various drugs 'double the quit rate,' understand that these results come from clinical trials where participants get their drugs free, where they are often called up with reminders and questions, where they develop relationships with the researchers and often want to please them, and where we know that many using the active drug are able to correctly guess they are on it or on the dummy drug,” said Chapman. “Studies of the use of quit drugs in 'real world' settings have not demonstrated that they have such success. A serious attempt at stopping need not involve using nicotine replacement therapy or other drugs or getting professional support.”

Chapman's findings were challenged by officials at the British antismoking group ASH and the U.K. Department of Health. “This study is inconsistent with a very well-established evidence base. Smokers that attempt to quit without assistance are significantly less likely to quit successfully than those who quit with support,” said a health department spokesperson, who said the unsupported-quit success rate was about 4 percent after one year.

The findings were published in the journal PLoS Medicine.