Ask a smoker what they get out of cigarettes and they are likely to talk about pleasure, contentment, and an overall good feeling. Nicotine, the active ingredient in cigarettes, is a stimulant. Used in low doses like those delivered by combustible cigarettes, stimulants activate the nervous system, resulting in enhanced arousal and alertness. Nicotine binding in the limbic system — the part of the brain that houses the pleasure and reward center — releases dopamine, resulting in feelings of euphoria. These effects combine to give smokers a boost in their mood.
In this context, new research from a team at Harvard University, that found that when smokers feel sad they reach for cigarettes and inhale longer and deeper, is not surprising. Cigarettes are a “solution” to the “problem” of sadness that smokers seem to learn to use effectively. This new research is the first to show that sadness elicits nicotine use much more than other negative emotions, and that sad feelings are not only associated with smoking, but can actually cause it.
Smoking may blunt an adaptive and necessary emotion
Sadness is a basic emotion, typically felt in response to loss. The experience of sadness and the underlying neurobiology is universal. Sadness that is too intense or too prolonged — i.e., depression — is a disorder that results in dysfunction. But normal sadness has an adaptive function: people experiencing sadness focus their attention internally and become better problem solvers.
The expression of sadness is physiologically determined. Humans can reliably read sadness on each other’s faces independent from cultural cues, and these signals provoke empathy from others — another benefit to the individual who is sad. In this regard sadness, while unpleasant, has its upsides; its universality is an indication of its survival advantage.
While smokers get immediate relief from sadness with a cigarette, that may come at a cost if they also lose these adaptive benefits. “Treatment” of sad emotional states with nicotine over time may also impair innate restorative responses, just as treatment of chronic pain with opioids results in many patients experiencing hyperalgesi