The research by Naresh M. Punjabi of the Johns Hopkins University School of Medicine, Baltimore, has revealed that smokers are four times as likely as nonsmokers to report feeling unrested after a nights sleep.

The study, appearing in the February issue of CHEST, the reviewed journal of the American College of Chest Physicians (ACCP), showed that smokers spend less time in deep sleep and more time in light sleep than nonsmokers, with the greatest differences in sleep patterns seen in the early stages of sleep.

According the report in the ScienceDaily, the stimulating effects of nicotine could cause smokers to experience nicotine withdrawal each night, which may contribute to disturbances in sleep.

“It is possible that smoking has time-dependent effects across the sleep period,” Punjabi said.