New research from Harvard University suggests that the emotion of sadness, compared to other negative emotions like anger or stress, plays an especially strong role in the drive to smoke cigarettes.

The research team conducted four studies to answer several questions regarding the nature of cigarette addiction: What drives a person to smoke? What role do emotions play in this addictive behavior? Why do some smokers puff more often and more deeply or even relapse many years after they’ve quit? If policymakers had those answers, how could they strengthen the fight against the global smoking epidemic?

While drawing from methodologies from different fields, the four studies all reinforce the central finding that sadness, more so than other negative emotions, increases people’s craving to smoke.

“The conventional wisdom in the field was that any type of negative feelings, whether it’s anger, disgust, stress, sadness, fear, or shame, would make individuals more likely to use an addictive drug,” said lead researcher Charles A. Dorison, a Harvard Kennedy School doctoral candidate.

“Our work suggests that the reality is much more nuanced than the idea of ‘feel bad, smoke more.’ Specifically, we find that sadness appears to be an especially potent trigger of addictive substance use.”

Senior co-author Dr. Jennifer Lerner, the co-founder of the Harvard Decision Science Laboratory and Thornton F. Bradshaw Professor of Public Policy, Decision Science, and Management at Harvard Kennedy School, said the research could have useful public policy implications.

For example, current anti-smoking ad campaigns could be redesigned to avoid images that trigger sadness and thus unintentionally increase cigarette cravings among smokers.

In one study, the researchers analyzed data from a national survey that tracked 10,685 people over 20 years. The findings revealed that self-reported sadness among participants was associated with being a smoker and with relapsing back into smoking one and two decades later. In fact, the sadder people were, the more likely they were to be smokers. Notably, other negative emotions did not show the same relationship with smoking.

In another study, the team wanted to test cause-and-effect: Did sadness cause people to smoke, or were negative life events causing both sadness and smoking? They recruited 425 smokers for an online study: one-third were shown a sad video clip about the loss of a life partner. Another third of the smokers were shown a neutral video clip, about woodworking; the final third were shown a disgusting video involving an unsanitary toilet.

All participants were asked to write about a related personal experience. The study found that individuals in the sadness condition — who watched the sad video and wrote about a personal loss — had higher cravings to smoke than both the neutral group and the disgust group.

A third study measured actual impatience for cigarette puffs rather than just self-reported cravings. Nearly 700 participants watched videos and wrote about life experiences that were either sad or neutral, and then were given hypothetical choices between having fewer puffs sooner or more puffs after a delay.

Participants in the sadness group proved to be more impatient to smoke sooner than those in the neutral group. That result built upon previous research findings that sadness increases financial impatience, measured with behavioral economics techniques.

Finally, a fourth study recruited 158 smokers from the Boston area to test how sadness influenced actual smoking behavior. Participants had to abstain from smoking for at least eight hours (verified by carbon monoxide breath test).

They were randomly assigned to sadness or neutral control groups; smokers sat in a private room at the Harvard Tobacco Research Laboratory, watched the sad video and wrote about great loss, or watched a neutral video and wrote about their work environment.

Then they smoked their own brand through a device that tested the total volume of puffs and their speed and duration. The results: smokers in the sadness condition made more impatient choices and smoked greater volumes per puff.

“We believe that theory-driven research could help shed light on how to address this epidemic,” Dorison said. “We need insights across disciplines, including psychology, behavioral economics and public health, to confront this threat effectively.”

The findings are published in the journal Proceedings of the National Academy of Sciences.

Source: Harvard Kennedy School