Mechanisms Through Which Treatments Operate
Despite the lack of significant
effects on overall abstinence, it is possible that the treatments operate via different
mechanisms. Mediation can occur in the absence of an overall effect of treatment on the
outcome (Mackinnon & Fairchild, 2009) and can provide important information about
mechanisms through which interventions might influence outcomes. Thus, the current study
examined mechanisms underlying MBAT vs. CBT and UC. First, we sought to examine
whether the three treatments had differential effects on proposed mechanisms. Second, we
investigated indirect effects of treatments through hypothesized mechanisms.
We hypothesized that both MBAT and CBT would lead to greater improvements in most
mechanisms compared to UC. In terms of differential effects of MBAT vs. CBT, we had
three specific predictions. First, given that mindful observation of unpleasant experiences is
thought to attenuate emotional reactivity, we expected that MBAT would more selectively
impact affective volatility. Second, because mindfulness practice involves conscious,
purposeful action (rather than “auto-pilot”), we hypothesized that MBAT would be more
likely to reduce certain aspects of dependence (i.e., automaticity, sense of loss of control).
Third, because a core component of mindfulness is attentional control training, we
hypothesized that MBAT would reduce attentional bias relative to CBT. Given past research
suggesting that both mindfulness and CBT might improve various mechanisms (e.g.,
emotions, agency), we did not have specific hypotheses about how MBAT vs. CBT might
differentially influence other variables.
Participants for the parent study were recruited in the greater Houston, Texas area using print
media. Eligible participants were at least 18 years old, currently smoked cigarettes (at least 5
cigarettes/day for the past year), were motivated to quit smoking in the next month, had a
viable home address and phone number, were able to read and write in English, produced an
expired carbon monoxide (CO) level of ≥ 8 parts per million (ppm), and provided collateral
contact information. Exclusion criteria were: contraindication for the nicotine patch, regular
use of tobacco products other than cigarettes, use of bupropion or nicotine replacement other
than the patches provided in the study, pregnancy or lactation, another household member
enrolled in the study, active substance dependence, current psychiatric disorder or currently
used psychotropic medications, or having received smoking cessation treatment in the
previous three months. The study was approved by the institutional review board, and all
participants provided written informed consent.