The study by Kansas State University psychology professor explains why for a smoker who enjoys drinking coffee, the nicotine may make a cup of joe even better.
Matthew Palmatier, assistant professor of psychology at K-State said that people might not be smoking to obtain a pleasurable drug state, but they may be smoking in order to regulate their mood.
He said this might be a reason why people find it hard to kick the butt.
"People have very regimented things they do when they smoke. If you think about where people smoke or who they smoke with, you realize that it occurs in very specific places, often with a specific group of people," said Palmatier.
"Maybe it's a reason why nicotine is so addictive - if you get used to having that extra satisfaction from things you normally enjoy, not having nicotine could reduce the enjoyment in a given activity," he added.
Palmatier is currently focussing on how this phenomenon can be used to better design tobacco addiction treatments, usually offered in patches and pills.
During the study, rats were allowed to self-administer nicotine by pushing a lever. The main source of light in their testing environment shuts off when the rats earn a dose of nicotine. After about a minute, the light comes back on to signal that more nicotine is available.
The analysis showed that the rats weren't really that interested in nicotine by itself.
"We figured out that what the rats really liked was turning the light off," Palmatier said.
"They still self-administered the nicotine, but they took more of the drug when it was associated with a reinforcing light," he added.
The study appears in the August issue of Neuropsychopharmacology.