Jesse Dallery

Effects of acute and chronic nicotine on impulsive choice in rats

Impulsive choice, or preference for small immediate reinforcers over large delayed reinforcers, has been associated with cigarette smoking. The direct effects of nicotine on impulsive choice in laboratory animals are unknown. We examined the effects of acute and chronic nicotine injections, and the termination of injections, on impulsive choice in rats. Five rats made choices between a one- and a three-pellet reinforcer in a discrete trials procedure. The delay to the smaller reinforcer was always 1 s. A computer adjusted the delay to the larger reinforcer until the pattern of choices reflected indifference between the two alternatives. We assessed the effects of acute and chronic nicotine (vehicle, 0.03, 0.1, 0.3 and 1.0 mg/kg nicotine). The latency to make the first response of the session increased under the acute 1.0 mg/kg dose. There were no consistent differences in the effects of acute and chronic nicotine on response latency and lever pressing during the delays between choices. Acute injections of nicotine dose-dependently increased impulsive responding. After chronic injections, impulsive responding was increased equivalently regardless of dose, and it was increased even in the absence of nicotine. After drug injections were terminated, behavior remained impulsive for about 30 drug-free sessions, and then responding gradually returned to baseline levels. The results suggest that increases in impulsive choice were not due to anorectic effects, response biases or changes in conditioned reinforcement. Nicotine may have decreased the value of delayed reinforcers. Chronic nicotine exposure produced long-lasting but reversible increases in impulsive choice.

Voucher-based reinforcement of opiate plus cocaine abstinence in treatment-resistant methadone patients: Effects of reinforcer magnitude.

The study tested a voucher-based abstinence reinforcement procedure for reducing opiate and cocaine use in a population of treatment-resistant opiate- and cocaine-abusing methadone patients. Vouchers exchangeable for goods and services were contingent on abstinence from both opiates and cocaine. In two conditions, participants could earn up to

Single-Case Experimental Designs to Evaluate Novel Technology-Based Health Interventions

374 or

An Internet-based abstinence reinforcement smoking cessation intervention in rural smokers

3,369 in vouchers for providing opiate- and cocaine-free urine samples. Participants received a daily 60-mg dose of methadone. The dose was increased in a second phase, and the voucher conditions were replicated. Analyses of both phases revealed trends toward greater abstinence under the high voucher condition and suggested that higher doses may enhance the efficacy of voucher reinforcement. The results show that reinforcement for abstinence from 2 drugs simultaneously can be effective even in a treatment-resistant population.

Contingency Management in the 21st Century: Technological Innovations to Promote Smoking Cessation

Technology-based interventions to promote health are expanding rapidly. Assessing the preliminary efficacy of these interventions can be achieved by employing single-case experiments (sometimes referred to as n-of-1 studies). Although single-case experiments are often misunderstood, they offer excellent solutions to address the challenges associated with testing new technology-based interventions. This paper provides an introduction to single-case techniques and highlights advances in developing and evaluating single-case experiments, which help ensure that treatment outcomes are reliable, replicable, and generalizable. These advances include quality control standards, heuristics to guide visual analysis of time-series data, effect size calculations, and statistical analyses. They also include experimental designs to isolate the active elements in a treatment package and to assess the mechanisms of behavior change. The paper concludes with a discussion of issues related to the generality of findings derived from single-case research and how generality can be established through replication and through analysis of behavioral mechanisms.

Advances in the Psychosocial Treatment of Addiction: The Role of Technology in the Delivery of Evidence-Based Psychosocial Treatment

The implementation of cigarette smoking abstinence reinforcement programs may be hindered by the time intensive burden placed on patients and treatment providers. The use of remote monitoring and reinforcement of smoking abstinence may enhance the accessibility and acceptability of this intervention, particularly in rural areas where transportation can be unreliable and treatment providers distant. This study determined the effectiveness of an Internet-based abstinence reinforcement intervention in initiating and maintaining smoking abstinence in rural smokers. Sixty-eight smokers were enrolled to evaluate the efficacy of an Internet-based smoking cessation program. During the 6-week intervention period, all participants were asked to record 2 videos of breath carbon monoxide (CO) samples daily. Participants also typed the value of their CO readings into web-based software that provided feedback and reinforcement based on their smoking status. Participants (n=35) in the Abstinence Contingent (AC) group received monetary incentives contingent on recent smoking abstinence (i.e., CO of 4 parts per million or below). Participants (n=33) in the Yoked Control (YC) group received monetary incentives independent of smoking status. Participants in the AC group were significantly more likely than the YC group to post negative CO samples on the study website (OR=4.56; 95% CI=2.18-9.52). Participants assigned to AC were also significantly more likely to achieve some level of continuous abstinence over the 6-week intervention compared to those assigned to YC. These results demonstrate the feasibility and short-term efficacy of delivering reinforcement for smoking abstinence over the Internet to rural populations.

INTERNET-BASED CONTINGENCY MANAGEMENT TO IMPROVE ADHERENCE WITH BLOOD GLUCOSE TESTING RECOMMENDATIONS FOR TEENS WITH TYPE 1 DIABETES

Information technology represents an excellent medium to deliver contingencies of reinforcement to change behavior. Recently, we have linked the Internet with a science-based, behavioral treatment for cigarette smoking: abstinence reinforcement therapy. Under abstinence reinforcement interventions, incentives are provided for objective evidence of abstinence. Several studies suggest that the intervention is effective in initiating abstinence. The intervention addresses limitations (access, cost, sustainability, and dissemination potential) inherent in traditional abstinence reinforcement delivery models. It can also be applied to vulnerable, at-risk populations, and to other behavior to promote health. Information technologies offer unprecedented and rapidly expanding opportunities to facilitate behavior change.

ISOLATING BEHAVIORAL MECHANISMS OF INTERTEMPORAL CHOICE : NICOTINE EFFECTS ON DELAY DISCOUNTING AND AMOUNT SENSITIVITY

The clinical community has a growing array of psychosocial interventions with a strong evidence base available for the treatment of SUDs. Considerable opportunity exists for leveraging technology in the delivery of evidence-based interventions to promote widespread reach and impact of evidence-based care. Data from this line of research to date are promising, and underscore the potential public health impact of technology-based therapeutic tools. To fully realize the potential of technology-delivered interventions, several areas of inquiry remain important. First, scientifically sound strategies should be explored to ensure technology-based interventions are optimally designed to produce maximal behavior change. Second, efficient and effective methods should be identified to integrate technology-based interventions into systems of care in a manner that is most responsive to the needs of individual users. Third, payment, privacy, and regulatory systems should be refined and extended to go beyond electronic medical records and telehealth/distance care models, and support the deployment of technology-based systems to enhance the quality, efficiency and cost-effectiveness of care. Fourth, the mechanisms underlying behavior change derived from technology-based treatments should be explicated, including new mechanisms that may be tapped via novel, technology-based tools. Such work will be critical in isolating mechanisms that are useful in predicting treatment response, and in ensuring that key ingredients are present in technology-based interventions as they are made widely available.

Internet-based contingency management increases walking in sedentary adults.

The current study used Internet-based contingency management (CM) to increase adherence with blood glucose testing to at least 4 times daily. Four teens diagnosed with Type 1 diabetes earned vouchers for submitting blood glucose testing videos over a Web site. Participants submitted a mean of 1.7 and 3.1 blood glucose tests per day during the 2 baseline conditions, respectively, compared to 5.7 tests per day during the intervention. Participants and their guardians rated the program favorably on a number of dimensions. The results suggest that Internet-based CM is feasible, acceptable, and effective to increase self-monitoring of blood glucose in teens.

A randomized controlled trial of smartphone-based mindfulness training for smoking cessation: a study protocol

Many drugs of abuse produce changes in impulsive choice, that is, choice for a smaller-sooner reinforcer over a larger-later reinforcer. Because the alternatives differ in both delay and amount, it is not clear whether these drug effects are due to the differences in reinforcer delay or amount. To isolate the effects of delay, we used a titrating delay procedure. In phase 1, 9 rats made discrete choices between variable delays (1 or 19 s, equal probability of each) and a delay to a single food pellet. The computer titrated the delay to a single food pellet until the rats were indifferent between the two options. This indifference delay was used as the starting value for the titrating delay for all future sessions. We next evaluated the acute effects of nicotine (subcutaneous 1.0, 0.3, 0.1, and 0.03 mg/kg) on choice. If nicotine increases delay discounting, it should have increased preference for the variable delay. Instead, nicotine had very little effect on choice. In a second phase, the titrated delay alternative produced three food pellets instead of one, which was again produced by the variable delay (1 s or 19 s) alternative. Under this procedure, nicotine increased preference for the one pellet alternative. Nicotine-induced changes in impulsive choice are therefore likely due to differences in reinforcer amount rather than differences in reinforcer delay. In addition, it may be necessary to include an amount sensitivity parameter in any mathematical model of choice when the alternatives differ in reinforcer amount.