While physical activity has been associated with decreased craving and increased abstinence rates in smokers, few published studies have examined the effects of exercise on recovery from other drugs such as cocaine. One factor that has impeded such research has been low levels of patient compliance with exercise protocols. One robust strategy for promoting and maintaining behavior change is contingency management or Behavioral Incentives (BI). Using behavior modification, BI delivers incentives (prizes, vouchers) contingent upon target behaviors such as cocaine abstinence (Higgins et al., 1994);treatment attendance (Svikis et al., 1997) and other pro-social behaviors (Kirby et al., 1998). While the literature is replete with studies demonstrating the benefit of BI compared to control conditions (Stitzer &Petry, 2006) with an average effect size d=0.42 (Prendergast et al., 2006), the translation of BI methods from research to clinical practice has met with some resistance. Contributing factors include philosophical differences (e.g., counselors feel extrinsic reinforcement undermines recovery) and practical barriers (e.g., monetary costs of incentives may be prohibitive). The latter concern was addressed by Petry (2005) who developed the """"""""fish bowl"""""""" method, which uses escalating variable ratio procedures to reduce per patient costs of BI with similar effect sizes. As a Stage 1 behavioral therapies development grant (Rounsaville et al., 2001), the primary aim is to pilot test a BI intervention designed to promote regular physical activity in a sample of women receiving inpatient treatment for SUDs. The target behavior, physical activity, will be objectively defined as 30 minutes of observed treadmill walking. Specifically, a pilot randomized clinical trial will compare rates of physical activity over a 6 week study period in a sample of N=50 women with Cocaine Dependence. Participants will complete baseline assessment, followed by random assignment to either the experimental (BI) or control (C) groups. All participants will attend a 30-min health and exercise education class, followed by equal daily access to on-site treadmills. Those randomized to BI, however, will also be eligible 3 days/week, to receive incentives for completing 30 minutes of treadmill walking. Incentives will be dispensed using Petry Fish Bowl methods. All treadmill walking will be monitored and recorded for both BI and C group women. Follow-ups will occur at study midpoint and completion (3 and 6 weeks post-randomization, respectively). Assessments will focus on drug craving, mood, stress, motivation/self-efficacy, and physical health and well being. We hypothesize that women in the BI group will complete more treadmill sessions and spend more time treadmill walking than those in the C group. As a Stage 1b therapy development RCT, study data will be used for effect size estimation in preparation for Stage 2 RCT. This dissertation proposal will provide benchmark data on the utility of BI for promoting physical activity. Additionally, if promising, it will promote exercise compliance, allowing scientists to better evaluate potential benefits of physical activity on treatment outcomes in women with SUDs.
To date, low rates of patient compliance have made it impractical to study whether regular exercise can contribute to positive outcomes in drug dependent women. The purpose of this study is to test the feasibility of using established behavioral incentives (BI) procedures to promote compliance with an exercise regimen in women with cocaine dependence and examine the potential benefits of exercise as an adjunct to substance abuse treatment. Results of the study will provide a greater understanding of strategies to enhance exercise adherence and the potential benefits of physical activity for cocaine dependent women. Overall, the proposed study will provide information that can be used to develop substance abuse treatment programs that directly utilize the mental and physical health benefits of physical activity.
