Using exercise to target maintenance factors of addictive behaviors

This research is prompted by the need to improve interventions for addictive behaviors. Research has identified several key biobehavioral mechanisms involved in the risk and maintenance of addiction, which are prime targets for novel interventions. The present dissertation aims to test whether we can effectively modify several factors predictive of relapse (e.g., low distress tolerance (DT), behavioral avoidance, and hypothalamic-pituitary-adrenal (HPA)-axis dysregulation) using physical activity interventions. The rationale for employing exercise for this application is supported by (1) decades of research attesting to the capacity for exercise to beneficially tap multiple biobehavioral systems, (2) more recent research supporting the clinical utility of exercise in substance use disorder treatment, and (3) emergent evidence supporting the potential of exercise as an appealing and accessible alternative or add-on to standard care. Study 1 extends the results of recent work by our group, which demonstrated efficacy for exercise to reduce anxiety sensitivity (AS), a form of distress intolerance reflecting vulnerability to somatic arousal. The results suggest that gender may be a moderator of this effect (Medina et al., 2014), with women responding less immediately than men. This observation underscores the need to further explore the treatment of distress-vulnerability in women, as well as potential merit in exploring alternatives to aerobic training. Accordingly, Studies 2 and 3 evaluated yoga for enhancing DT in females for whom distress vulnerability served to exacerbate maladaptive coping tendencies (e.g., smoking, overeating). Study 2 served as a proof of principle, wherein we examined the efficacy of Bikram yoga for enhancing DT in a sample of females with an elevated tendency to eat in response to stress or negative affect (i.e., conceptualized as an addictive behavior). Results were consistent with our hypothesis, showing that yoga enhanced self-reported emotional DT. Moreover, we found yoga primarily increased the absorption sub-facet of DT (defined as tendency for distress to absorb attentional resources), which, in turn, mediated reductions in self-reported emotional eating (Medina et al., 2015). In Study 3, we applied an 8-week hatha yoga (Vinyasa flow) intervention, aiming to address the contribution of elevated AS to early relapse in female smokers by targeting cortisol declines during the withdrawal phase of a quit attempt. Results did not support yoga as efficacious for altering cortisol, ameliorating subjective withdrawal, or achieving continuous abstinence post-quit. We speculate this was in part due to poor intervention adherence, highlighting the importance of including intervention components to address motivation for health behavior change. We discuss other limitations and future directions from our findings across studies.