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.

I am an experimental psychologist focusing on laboratory models of adolescent smoking and the behavioral economics of tobacco use. My research program centers on the field of tobacco regulatory science and supports the science base that may lead to a reduction in nicotine in all commercially available cigarettes in the U.S. Such a bold public health initiative would directly prevent cancer by shifting individuals away from combustible tobacco products and toward noncombustible products such as e-cigarettes and, ideally, towards cessation.

Research Area 1: Modeling the impact of nicotine reduction on adolescent and young adult smokers in the laboratory

The FDA is considering mandating a reduction in the level of nicotine in cigarettes, but very little work had been done on how this would affect youth. My work has focused on addressing this gap. My line of research was the first to demonstrate that nicotine reduction would not acutely increase the abuse liability of cigarettes in adolescent smokers, and would not lead to intolerable withdrawal symptoms (Cassidy et al., 2018). We also found that subjective evaluations were decreased dose-dependently, such that lower nicotine doses were rated as less satisfying and less effective at reducing craving than higher doses. Using a behavioral economic purchase task, we found that low nicotine content cigarettes were rated as significantly less reinforcing than adolescent participants’ usual brand cigarettes (Cassidy et al., 2019a). Taken together, these results suggest that acutely, adolescent smokers will obtain withdrawal relief from VLNC cigarettes; while at the same time, VLNC cigarettes appear to have lower abuse liability than usual brand cigarettes in this population given the reduced positive subjective and reinforcing effects. These results led to my being invited to a give a webinar on the impact of nicotine reduction on youth through which was attended by over 100 participants and archived on the TRSKnowledge.org website, the main clearinghouse for tobacco regulatory science training and resources.

To model the potential long-term effects of nicotine reduction on young adults, I conducted a secondary analysis of the moderating effect of age on response to nicotine reduction in a landmark trial that asked participants to use low-nicotine cigarettes for six weeks. These data suggested that nicotine reduction may hasten the transition from combustible cigarettes more quickly in young adults relative to older adults (Cassidy et al., 2019b). This work was replicated and extended in a trial comparing gradual versus immediate reduction that I presented at the TRS conference in October of this year. I am currently at work on a longer-term clinical trial of the effects of nicotine reduction in 15-19 year olds; this will be the first trial of its kind in youth. Based on this unique experience, I was invited to give an SRNT Pre- Conference workshop presentation on behalf of the Adolescent Network entitled “Recruiting and Retaining Adolescents in Tobacco Control Research: Challenges and Opportunities” and to re-present this work to a larger audience via the SRNT Adolescent Network webinar series. I am also currently a Co-Investigator on the Center for Evaluation of Nicotine in Cigarettes grant, which is the leading Center for innovation in nicotine reduction research.

One potential challenge for a nicotine reduction policy is that the risk for addiction from reduced-nicotine content cigarettes is lower, but these products still contain carcinogens and are harmful to health. Working with a BSS graduate student colleague, Rachel Denlinger-Apte, we recently analyzed whether adolescents in my K01 study had differential perceived health risk as a function of nicotine dose (Denlinger-Apte, Cassidy et al., 2019). This work showed that nicotine reduction may lead to lower cigarette health risk perceptions in adolescent smokers, which underscored the need for the FDA to engage in nuanced public health messaging.

In September 2019, 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. This work has the potential to be of great impact for the field, as adolescents are a priority focus for tobacco control efforts.

 

Research Area 2: Leveraging behavioral economics to enhance tobacco regulatory science and understanding of dual use patterns

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. The initial study in this program of research was supported by a Postdoctoral Development Grant from the University of Vermont TCORS 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 (Cassidy et al,. 2017;2020). This work demonstrated that the most frequently used e-cigarette purchase tasks, which ask participants how many puffs of their e- cigarette they take in a day, is not ideal; rather, the unit of purchase, either in bottles of e-liquid or Juul pods, helps participants more accurately estimate their use. The next stage of this research was funded by an R03 grant from NIDA which validated a purchase task for e- cigarettes in the laboratory, and showed that a measure based on units of purchase rather than puffs of an e-cigarette better modeled actual use behavior. 

With a colleague, Dr. Elizabeth Aston, I was awarded a Research Excellence Award from CAAS to support the collection of pilot data on a novel behavioral economic task that we developed to assess concurrent marijuana and cigarette purchasing in young adults. We demonstrated that individual differences in cannabis and tobacco purchasing exist, such that, for some individuals, cannabis and tobacco act as substitutive products, while for other individuals, they may be independent of each other, or even act as complements. This work has important implications for determining the risk of unintended consequences in the context of the changing tobacco and marijuana legal landscapes.

I am funded by an R01 from NIDA (R01DA047356, MPI Cassidy/Colby), “Impact of Nicotine Reduction on Adolescent Cigarette Use, Alternative Tobacco Use, and Harm from Tobacco". I was previously supported by a 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

Associate Professor

Center for Alcohol and Addiction Studies