Neural Stress Reactivity Relates to Smoking Outcomes and Differentiates between Mindfulness and Cognitive Behavioral Treatment (Kober et al. 2016)
According to the World Health Organization, cigarette smoking contributes to 5.4 million deaths per year and is the most preventable cause of morbidity and mortality in developed nations. While smoking rates are decreasing overall, approximately 1 in 5 Americans still continue to smoke. There is promising evidence that 70% of smokers would like to quit, but less than 5% of unassisted attempts at quitting are actually successful.
Scientists have begun to focus on the mechanisms of stress and how it relates to smoking relapse. Previous research has established that acute moments of stress are linked to drug use and relapse and the magnitude of the stress response can actually predict relapse. Given this body of evidence, several smoking cessation treatments target stress as a potential mechanism for relapse prevention.
A previous study directly compares two such treatments for smoking cessation. The first is Freedom From Smoking (FFS), which is a form of a cognitive-behavioral treatment developed by the American Lung Association. This treatment uses cognitive strategies for coping with cravings and stress and is divided into stages of preparation, action, and maintenance. The FFS treatment that it is being compared to is Mindfulness Training (MT) for smoking, where the focus is to be present and accept both negative states and cravings, without the attempt to necessarily change their form or frequency.
There were two parts to the study. The first part of the study compared the two treatments and showed that Mindfulness Treatment (MT) was more effective at reducing smoking than Freedom From Smoking (FFS) during the treatment and at a 3-month follow-up. The second part of the study examined how stress reactivity in several brain regions related to smoking outcomes between the two types of interventions. To test this, a small subset of participants from the first part of the study (N=23) read a script of a personalized stress-inducing or neutral/relaxing scenario in an fMRI immediately after completing their treatment, and then repeated the tasks again 3 months later. Perceived stress and cravings were also assessed throughout the study.
Both groups showed neural activity in similar brain regions to the stress-inducing scenario, including the amygdala, mid-insula, and hippocampal regions. There were no significant differences of neural activity in the neutral/relaxing scenarios. Additionally, both groups showed that neural activity during these stressful scenarios had a negative correlation to smoking reduction. In other words, the greater their brain activity responded to stress, the less likely they were to have reduced their smoking throughout the study.
However, for the stress-inducing tasks, the Freedom From Smoking group showed greater stress reactivity in these same neural regions. These findings, coupled with the results that the Mindfulness Training group had a greater reduction in smoking, provide evidence that reducing stress reactivity at the neural level may be one of the primary mechanisms that make Mindfulness Training more effective for smoking cessation.
There are notable neurological differences between the two treatment options. For instance, the Freedom From Smoking intervention, which is a cognitive-behavioral therapy, activates the prefrontal cortex of the brain, which stress and forms of psychopathology, like addiction, can compromise its functioning. Conversely, Mindfulness Training, which relies on acceptance and being present, does not rely on the same prefrontal cortex and therefore might be more appropriate for clinical populations who deal with both stress and addiction.
This study is the first to provide evidence to this model linking stress reactivity at the neural level to reduction of smoking in mindfulness treatments. This adds to an existing body of mindfulness research on stress reactivity in the brain and might provide further evidence for the clinical application for mindfulness-based interventions.