DURHAM, N.C. -- Nicotine may improve the symptoms of depression in people who do not smoke, Duke University Medical Center scientists have discovered.

The finding does not mean that people with depression should smoke or even start using a nicotine patch, the researchers caution. They say that smoking remains the No. 1 preventable cause of death and disability in the United States, and that the addictive hazards of tobacco far outweigh the potential benefits of nicotine in depression. But the finding suggests that it may be possible to manipulate nicotine's effects to safely reap its potential medical benefits, according to the researchers.

As an example of the drug's potential, they said, pharmaceutical companies already are developing compounds for treating other brain disorders by mimicking the beneficial properties of nicotine while avoiding its addictive nature. "The hope is that our research on nicotine will spur the development of new treatments for depression, which is a huge public health problem," said lead study investigator Joseph McClernon, Ph.D., an assistant research professor of medical psychiatry and researcher at the Duke Center for Nicotine and Smoking Cessation Research.

"Our study also provides evidence that smokers may indeed smoke, in part, to improve their mood -- a notion that has been quite controversial in the field," he said. 2001-2006 Duke University Medical Center.