Commentary on Hajek et al. (2010): investigating the stress reduction in smoking cessation.

As detailed by Hajek, Taylor, and McRobbie [1], smokers report that stress relief is a fundamental reason for continued use of tobacco. In this study, stress levels were measured a year apart in order to investigate how this construct changed among smokers who successfully quit compared to those who relapsed. This is a particularly important area to investigate as many smokers believe and report that smoking cigarettes alleviates stress. Hajek and colleagues present a novel approach to better understanding this phenomenon. The investigation clearly adds to our understanding of this relationship and provides several areas for future research, most notably with respect to studying additional populations and employing more rigorous measurement of the construct of stress. Additional Populations Hajek and colleagues used two groups to test their hypothesis: Individuals recently hospitalized for a myo-cardial infarction (MI) and those presenting to the hospital for scheduled coronary artery bypass surgery (CB). These groups are well suited to study the smoking-stress relationship as abstinence rates are quite high in these groups. However, future research in this area would benefit from the study of additional populations. Specifically , some may argue that MI patients show an atypical stress response due to their cardiac event as evidenced by greater cortisol secretion, higher evening cortisol levels and a flattened diurnal slope [2]. Further, it is possible that the planned-surgery group (CB) may have experienced anticipatory anxiety as a result of their impending surgery, which has been documented to increase cortisol levels 25–100% [3]. Future studies should examine groups who have not recently experienced a traumatic or life-threatening event that may have precipitated smoking cessation. Such studies are necessary as it is possible that participants who took part in the study by Hajek and colleagues experienced stress levels that were artificially elevated due to the traumatic event (MI/CB) at the time of the first assessment. Given this circumstance, it seems logical that follow-up assessment one year later would show lower levels of stress, not necessarily due to smoking cessation, but rather from an improved overall health status. This may be particularly helpful with regard to the MI group, as those experiencing MI have been shown to have disproportionately high levels of post-traumatic stress (10–15% prevalence, [4–6]), which is a well-documented risk factor for smoking relapse [7]. Ruling out this rival hypothesis would significantly enhance the findings reported by Hajek and colleagues. As mentioned above, the authors were …