Nicotine withdrawal may reduce response to rewards across species, according to a recent study.

Cigarette smoking is a leading cause of preventable death worldwide and is associated with nearly 440,000 deaths in the United States each year, according to the U.S. Centers for Disease Control and Prevention, but nearly 20 percent of the U.S. population continues to smoke cigarettes. While more than half of U.S. smokers try to quit every year, less than 10 percent are able to remain smoke-free, and relapse commonly occurs within 48 hours of smoking cessation.

American researchers found that nicotine withdrawal similarly reduced reward responsiveness in human smokers -- particularly those with a history of depression -- as well as in nicotine-treated rats.

Response to reward is the brain's ability to derive and recognize pleasure from natural things such as food, money and sex. The reduced ability to respond to rewards is a behavioral process associated with depression in humans.

For the study, the research team measured a behavior that can be similarly quantified across species like humans and rats, the responses to rewards during nicotine withdrawal.

"The fact that the effect was similar across species using this translational task not only provides us with a ready framework to proceed with additional research to better understand the mechanisms underlying withdrawal of nicotine, and potentially new treatment development, but it also makes us feel more confident that we are actually studying the same behavior in humans and rats as the studies move forward," researcher Michele Pergadia, one of the lead authors of the study, said in a statement.

Pergadia emphasized that the ultimate goal of this line of research is to improve treatments that manage nicotine withdrawal-related symptoms and thereby increase success during efforts to quit.

"Many smokers are struggling to quit, and there is a real need to develop new strategies to aid them in this process. Therapies targeting this reward dysfunction during withdrawal may prove to be useful," said Pergadia.

The findings were recently published in JAMA Psychiatry.