Researchers have suggested that smoking may help restore self-control by improving smokers' positive mood, which may contribute to tobacco addiction. When researchers at Moffitt Cancer Center in Tampa, Fla., deplete smokers' self control, they found that smoking a cigarette helps restore their self-control. The study exposed a test group and a control group - totalling 132 nicotine dependent smokers - to an emotional video depicting environmental damage. One group in the study expressed their natural emotional reactions (no depletion of self-control) while the second group suppressed their responses (self-control depletion). Half of the participants in each group were subsequently allowed to smoke a cigarette. Everyone then was asked to complete a frustrating task that required self-control. "Our goal was to study whether tobacco smoking affects an individual's self-control resources," said lead author Bryan W. Heckman, M.A., a graduate student at the Moffitt Tobacco Research and Intervention Program and the Department of Psychology at the University of South Florida. "We hypothesized that participants who underwent a self-control depletion task would demonstrate less persistence on behavioural tasks requiring self-control as compared to those with self-control intact, when neither group was allowed to smoke. However, we also hypothesized that we would not find this performance decrement among participants who were permitted to smoke," Heckman stated. The results of the study supported the investigators' hypotheses. "We found that smoking did have a restorative effect on an individual's depleted self-control resources. Moreover, smoking restored self-control, in part, by improving smokers' positive mood," said Heckman. According to the researchers, evidence is mounting to suggest that self-control is a limited resource that acts like a muscle - expending self-control on a task has the short-term effect of depleting the resource, making it more difficult to engage in another task that requires self-control. While nicotine has been found to enhance performance on a variety of cognitive activities, such as motor abilities, attention and memory, this study was the first to evaluate the effects of smoking on self-control. It suggests that the desire to restore depleted self-control may contribute to smokers' addiction to tobacco. "Smoking is obviously a maladaptive way to restore self-control," said study co-author Thomas H. Brandon, Ph.D., chair of the Department of Health Outcomes and Behaviour at Moffitt Cancer Center, and psychology professor at USF. "Finding other ways to relax or enhance one's mood would be much healthier alternatives. In fact, even raising glucose level - perhaps by consuming a sugary drink - has been shown to restore self-control," he added. This study also suggested that smokers wanting to quit might benefit from learning such alternative self-control restoration strategies as a way to reduce their dependence on tobacco. The authors concluded that smoking cessation treatments would benefit by further research aimed at identifying how smoking restores self-control, as well as identifying additional alternative strategies for strengthening or restoring self-control.