My research focuses on tobacco regulatory science, including the potential efficacy of very low nicotine cigarettes, in young adult and adolescent smokers. I also work within a behavioral economic framework to understand e-cigarette use.

My interest in tobacco and nicotine began in the context of learning about drugs as reinforcers. Drugs make you feel good and make you forget about feeling bad, and these positive qualities maintain and reinforce drug-taking behavior. In the context of intoxicating drugs- alcohol, cocaine, opiates- the positive qualities seemed clear, and provided a counterweight to the obvious negative outcomes of drug use. However, smoking always struck me as a strange case. To a non-smoker, the positive qualities seem so much less obvious, and yet the negative outcomes- like lung cancer, heart disease, and social stigma- seemed to loom large. At the same time, I wanted to understand what factors maintained smoking behavior, and how these factors could be manipulated experimentally in the laboratory. I developed an overarching interest in using behavioral laboratory methods to understand smoking behavior, and to applying this knowledge to helping people stop smoking.

 

Research Background. I completed my graduate work in behavioral pharmacology with nonhuman animals at the University of Florida. Under Dr. Jesse Dallery, my training was focused on the translational application of laboratory work. My master’s thesis and dissertation were focused on behavioral economic analyses of the effect of nicotine on responding for food and other reinforcers. My dissertation work emphasized the role that nicotine plays not only as a reinforcer in its own right, but as a substance that enhances the value of other reinforcers in the environment, helping to further explain the maintenance of smoking behavior. Both my Master’s and dissertation studies were published in the Journal of the Experimental Analysis of Behavior; I recently ended my tenure as an editorial board member at that journal. These studies honed my expertise in behavioral economics, a method of understanding the persistence of behavior in the face of increasing costs, as both a theoretical framework and a method for analyzing individual difference in drug response. These experiences give me a strong grounding in rigorous laboratory methods, and began my interest in behavioral economics which continues to inform my work.

 

After receiving my doctoral degree in 2013, I took a postdoctoral fellowship position at Brown University, working with Dr. Suzanne Colby and Dr. Jennifer Tidey at the Center for Alcohol and Addiction Studies. During my postdoc, I shifted focus to human laboratory work and specifically to adolescent smoking. It was at Brown that I first learned about the FDA’s Center for Tobacco Products and how tobacco regulation could impact behavior by mandating a reduction of nicotine in all available cigarettes. From a behavioral perspective, reducing the primary reinforcer (i.e., nicotine) in cigarettes should reduce the overall reinforcing efficacy of cigarettes, and shift behavior away from these deadly products. I worked on a large clinical trial of the effects of reduced nicotine cigarettes on smoking behavior in adults (Center for the Evaluation of Nicotine in Cigarettes; CENIC) and published a human laboratory study with adolescents examining the effects of alternative reinforcer availability on adolescent smoking choice in Nicotine and Tobacco Research. As I gained clinical laboratory skills and saw the promise of nicotine reduction strategy in reducing combustible tobacco product use, I developed a K01 grant proposal with my mentors that focused on extending the promising results of models of a nicotine reduction policy in adults to adolescents.

 

In 2014, I was awarded a K01 award from the National Cancer Institute (K01CA189300) to begin work on a program of research examining the effects of nicotine reduction on adolescent smoking behavior, both in the laboratory and in a small field trial. As the vast majority of smokers begin when they are under 18, testing this policy in adolescents is crucially important for the FDA as they work to lay the empirical foundation for a potential nicotine reduction mandate. The first study from that grant showed that acutely, nicotine dose in cigarettes ranging from very low to normal commercial nicotine levels were equally as effective in reducing abstinence-induced withdrawal and negative affect; however, lower nicotine cigarettes were rated as less satisfying and were attenuated craving to a lesser degree. The results of the study are published at Drug and Alcohol Dependence. I have also developed the first trial of very low nicotine cigarettes in adolescents (NCT02587312), which is ongoing. I have also analyzed data from the CENIC project to assess the effects of nicotine reduction on young adult smoking (Cassidy et al., 2018). I am currently collaborating with my K01 mentors Drs. Suzanne Colby, Jennifer Tidey, and Dorothy Hatsukami as a Co-Investigator on the Center for Evaluation of Nicotine in Cigarettes grant renewal (U54 DA031659). The project is a study of the impact of nicotine dose and flavors in an adolescent laboratory model of e-cigarette choice in the context of reduced nicotine cigarette availability as model of which e-cigarette characteristics may be most likely to drive behavior away from combustible cigarette use. Recently, I was awarded an R01 with Dr. Suzanne Colby as MPI that will examine the potential effects of a nicotine reduction policy on youth use of both cigarettes and alternative tobacco products. This project will assess the total harm from tobacco in the context of nicotine reduction by assessing to what extent nicotine reduction leads youth to change their use of alternative tobacco products such as e-cigarettes and little cigars, and how this change in behavior may lead to changes in overall toxicant exposure. I believe our work in this area has the potential to be of great impact for the field as adolescents are a priority focus for tobacco control efforts.

 

Another area of research that I am passionate about is the role of e-cigarettes in tobacco regulatory science, and in particular the role behavioral economics can play in helping to understand these and other novel tobacco products. I have been involved in work that uses a validated behavioral economic method of assessing demand for cigarettes to determine whether nicotine reduction may decrease the reinforcing efficacy of cigarettes in adults and adolescents (Smith, Cassidy et al., 2017; Cassidy et al., In Press). As the reinforcing efficacy of cigarettes may be decreased by nicotine reduction, the relative value of alternative tobacco products will increase; thus, validated methods for assessing the reinforcing efficacy of novel tobacco products are needed. I was initially awarded a Postdoctoral Development Grant from the University of Vermont TCORS (PI: Stephen Higgins) to use qualitative methods to inform the development of a behavioral economic measure for e-cigarettes, which led to a publication on the best units of measurement of e-cigarette use in Tobacco Regulatory Science. On the strength of these preliminary data I was awarded an R03 grant from NIDA (R03DA041820) to further validate a purchase task for e-cigarette use, and I recently presented the results in a symposium at the Tobacco Regulatory Science meeting at NIH. To further this promising line of work, I recently submitted an R01 as PI to the Electronic Nicotine Delivery Systems (ENDS) RFA that proposes to use this task in the context of a longitudinal examination of dual cigarette and e-cigarette use in young adults which was scored.  The e-cigarette purchase task has generated a lot of interest from researchers who have gone on to use it in their protocols, and this has facilitated collaboration with other colleagues in this area which I hope to continue.

 

Future Directions. Currently, I am focused on continuing to grow my research program in the area of adolescent smoking, tobacco regulatory science, and behavioral economic explorations of alternative product use. With a colleague at Brown, Dr. Elizabeth Aston, this Fall I was awarded a Research Excellence Award from CAAS to facilitate the collection of pilot data on a novel, innovative behavioral economic task to assess concurrent marijuana and cigarette purchasing in young adults that we developed. The pilot study is in support of an R01 submission which received an initial score and has been resubmitted. This innovative work underscores my continued passion for extending behavioral economic theory beyond traditional cigarette use. I am also interested in expanding the reach of tobacco regulatory science to other vulnerable populations beyond adolescents, including by incorporating more ethnically diverse samples in trials of e-cigarette and low nicotine content cigarettes use, to better understand how tobacco regulations will affect all individuals.

 

I am funded by the National Cancer Institute on a Mentored Research Scientist Career Development Award in Tobacco Control Regulatory Research (K01) award entitled “Evaluation of Very Low Nicotine Content Cigarettes in Adolescent Smokers” (K01 CA189300, PI Cassidy) and a Tobacco Regulatory Science Small Grant Program for New Investigators (R03 DA041820, PI Cassidy).

 

Research Excellence Award, Brown University, 2017

APA NIDA/NIAAA Early Career Scientist Travel Award, 2016

Loan Repayment Program, National Institutes of Health, 2014       

Postdoctoral Development Award, University of Vermont Tobacco Center for Regulatory Science, 2014

Graduate Student Teaching Award, University of Florida, 2013

Behavior Analysis Research Award, University of Florida Department of Psychology, 2013

College of Liberal Arts and Sciences Alumni Fellow, University of Florida,  2008 – 2012

Grinter Fellowship Awardee, University of Florida, 2008                                                                                                                                                                 

Society for the Advances of Behavior Analysis Student Presenter Grant, Association for Behavior Analysis International, 2008, 2010

Phi Beta Kappa National Honor Society Inductee, 2007

University Scholars Program Student Grant Recipient, University of Florida, 2007 – 2008

Assistant Professor (Research)

Center for Alcohol and Addiction Studies