Lab Director

Hollis Karoly, Ph.D. (she/her)

Broadly, my research aims to characterize neural, molecular and behavioral mechanisms underlying the etiology of alcohol use disorders, in an effort to inform treatment development. More specifically, I am interested in how functional impairments along the microbiota-gut-brain-axis (MGBA; which refers to bidirectional interactions between gut microbes, endocrine, autonomic, enteric, immune and central nervous systems) may promote alcohol use behavior and serve as potential treatment targets. In recent years, my work has increasingly emphasized the role of the endogenous cannabinoid system – which is distributed heavily throughout the brain and gut – in the context of alcohol use disorders.

Thus, I am conducting several studies measuring the impact of phytocannabinoids (primarily cannabidiol [CBD] and tetrahydrocannabinol [THC]) on behavioral phenotypes related to alcohol use disorder (alcohol consumption, craving, intoxication) and on biomarkers across the MGBA (brain structure and function, peripheral inflammation, intestinal permeability, gut microbial composition). Outside of work, I try to spend as much time as I can enjoying the Colorado mountains with my husband and son.

Graduate students

Meggan Drennan, M.S. (she/her)

I am a Ph.D. candidate in the Cognitive Neuroscience program and currently conducting my dissertation research through heading the ORCA study. Prior to arriving at CSU, I received my B.S. in Behavioral Neuroscience from St. Edward’s University in Austin, Tx where I discovered my love of research and decided to pursue a career in exploring the physiological mechanisms behind psychology and behavior. I relocated to Fort Collins and completed my Master’s degree in Biomedical Sciences before joining the ENIGMA lab for my Ph.D. My research combines psychological and biological measures to investigate relationships between the gut microbiome, brain and behavior as it is influenced by alcohol and cannabis use. Outside of academia, I am the mother of 2 beautiful children and enjoy writing music, playing the piano and singing, as well as creating artwork in multiple forms.


Cianna Piercey, M.A. (she/they)

I am a fourth-year doctoral candidate in the Counseling Psychology Ph.D. program at CSU and the director of the DISCO and kratom/kava studies. I also assist on the mobile lab studies in varying capacities and have a number of collaborative projects I contribute to spanning cannabis, kratom, and psychedelic substances. Broadly, my research leverages mixed methodologies (e.g., drug administration, ethnography, participant observation), and advanced quantitative and qualitative analytic techniques, to better understand substance use behavior and drug pharmacology across a range of substances—particularly emerging botanicals or other drugs about which limited data currently exist. I am also especially interested in understanding the acute effects associated with specific drug combinations and how individuals might mitigate risks within the context of polysubstance use. For example, my master’s thesis focused on the development of a novel inventory of polysubstance use protective strategies for use within club and festival contexts. Ultimately, all of my work is conducted through a harm reduction lens, which includes community outreach, advocacy, and distribution of evidence-based drug information and resources. Outside of research, I am a therapist at a local substance use treatment clinic and serve in a number of professional service roles. Currently, I am a student representative for APA division 28 (Psychopharmacology and Substance Use) and the division 28 social media chair. I also serve on the student committee within APA division 50 (Society of Addiction Psychology). In my down time, I enjoy seeing live music, being outside (especially camping and hiking), making art, and spending time with friends and family.


Vanessa Stallsmith, M.S. (she/her)

I am a fourth-year student in the Counseling Psychology Ph.D. program and the lead graduate researcher on the FRACTAL and EXCEL studies. I moved to Colorado in 2016 to complete my dual B.A. in Neuroscience and Psychology at the University of Colorado, Boulder (sko buffs!). I am interested in researching novel therapeutic approaches to alleviate mental health disorders and promote overall wellness. I am fascinated by the intersection of behavioral health and physical well-being and aspire to someday work in a primary care facility or academic medical center where I can incorporate exercise, diet, and counseling in my approach to “whole-person” care. When I’m not working, I love to celebrate my body through movement. As such, I’m typically at the gym or on a hike with my partner. I love being outdoors and exploring this beautiful state! I’m also a self-proclaimed foodie and enjoy trying new recipes and feeding the people I love.


Eleftherios (Lefty) Hetelekides, M.S. (he/him)

I started the Counseling Psychology Ph.D. program in Fall 2022 and am currently the lead graduate researcher on the NECCTAR and RISE studies. My previous research experiences include preclinical work related to the endocannabinoid system, neuroimaging, and neuropharmacology in mouse and rat models of addiction. I have also been involved in clinically focused substance use research related to personality, protective behavioral strategies/harm reduction, drug-related behaviors, craving, and neuroelectrophysiology (i.e., EEG). For my PhD and career, I am interested in exploring biopsychosocial mechanisms related to psychopathology, substance use/addiction, and behavior change. In my free time I enjoy being outside, exercising (especially rock climbing!), chilling with friends, having philosophical discussions, playing video games, and cooking delicious food with minimal effort in my air fryer.


Claire Pince (she/her)

I am a second-year student in the Counseling Psychology Ph.D. program and a graduate research assistant on the RISE study. Before coming to CSU, I received my B.A. in Neuroscience from the University of Pennsylvania in 2021 and subsequently completed a 2-year postbaccalaureate research training program at the National Institute on Drug Abuse in Baltimore. My research background is predominantly preclinical, with a focus on developing novel pharmacotherapeutics for alcohol use disorder, and I am interested in studying substance use and co-occurring disorders from a biopsychosocial and harm reduction-aligned perspective. Currently, I am working on projects exploring the relationship between alcohol/cannabis use and disordered eating behaviors. In my free time, I enjoy baking/cooking, roller skating, singing, and hiking.


John (JD) Curtis (he/him)

I am a first-year student in the Counseling Psychology Ph.D. Program here at CSU. I graduated from Arizona State University with a B.S. in psychology. My research interests are in comorbid substance misuse & trauma, harm reduction, therapeutic potentials of psychedelics & cannabis, and in health & treatment disparities among Veteran & LGBT populations. In my free time I enjoy pursuing volunteer experiences in harm reduction or community service spaces. Additionally, I enjoy meditational experiences, live music, and can almost always otherwise be found in a hammock with a good book.

lab manager

Katelyn Weldon (she/her)

I recently graduated from Colorado State University with a Bachelor of Science in Psychology. Currently, I am taking time away from school to gain experience as the ENIGMA Lab’s lab manager as I prepare to apply for clinical psychology doctoral programs this fall. My research interests are focused on investigating the biopsychosocial factors underlying the comorbidity of substance use and eating disorders. Specifically, I am interested in their related personality characteristics and neurobiological mechanisms. Additionally, I am passionate about addressing research and treatment disparities within marginalized communities and advocate for harm reduction as a central approach in substance use treatment.

In my free time, you will find me exploring Colorado’s beautiful outdoors with my dog, reading, watching bad reality TV, or enjoying live music.

Research Assistants

Chandler Hand (she/her)

Hey! My name is Chandler and I am an undergraduate student at CSU, where I am currently studying Psychology with an Addiction Counseling concentration. My current interests involve the intersection of mental health, addiction, and use of psychoactive medication (which is why I am so stoked to be a part of the ENIGMA Lab Team). In the future, I plan to attend graduate school in order to obtain my LPC. In my free time, I enjoy indulging in various outdoor adventures such as skiing, rock climbing, and various whitewater activities


Fiona Gilfillan (she/her)

I am an undergraduate Psychology major here at CSU, following the Mind, Brain, and Behavior concentration. I plan to pursue a PhD in Cognitive Neuroscience and conduct research. I am particularly interested in psychedelic neuroscience and neurophenomenology. In the future, I hope to conduct research that leads to a better understanding of the neural correlates of consciousness through research with neuroimaging and psychedelics. In my free time, I like to build Legos, do puzzles, binge TV, and go to drag shows!


Joseph Cameron (he/him)

I am a 3rd year psychology student at CSU. I was born and raised here in Fort Collins. I am interested in the study of addiction and counseling. My current interest is in methamphetamine addiction, harm reduction, and the improvement of treatments for those who have substance use disorder. I plan to attend graduate school and get a masters or Ph.D. in Clinical and Counseling Psychology. In my spare time I like to watch a good Netflix movie with my husband and our dog.


Ella Gravante (she/her)

Hi! I’m Ella, and I’m currently in my junior year at CSU. I’m majoring in biochemistry and minoring in bioinformatics, and I intend to pursue graduate school after I finish. I’m interested in exploring the biochemical mechanisms involved in human consciousness, particularly in relation to novel mental health treatments using psychoactive substances. To me, harm reduction initiatives and academic research go hand-in-hand, and I’m very excited to be working on both sides during my time here. Outside of ENIGMA, I also am a part of a project investigating novel approaches to medical imaging using machine learning in electrical impedance tomography. When I’m not in class, I love hiking and backpacking, and I volunteer at a harm reduction organization here in Fort Collins!


Marina Sazonova (she/her)

My name is Marina, I was born in Kharkiv, Ukraine, I immigrated to Los Angeles when I was 6, and found myself in Colorado in 2017. I recently graduated CSU with a Bachelor’s degree, with a concentration in cellular/molecular biology and genetics. I hope to spend my career furthering research where I can apply my passion for molecular biology and genetics to further the understanding of our world, the human experience, and the connections between physiology and psychology. As such, I have a strong interest in working with interdisciplinary and biopsychosocial studies. I am taking a couple of gap years to gain research experience, find the best graduate program for me, and to volunteer in Ukraine as much as I can. I spend my free time connecting with nature, learning new things, playing video games, and spending time with my husband and our two cats.


Bella Packwood (she/her)

I am a fourth-year undergraduate psychology major here at CSU with a concentration in mind, brain and behavior.  I am particularly interested in neurobiology, mental health, and addiction, which is what drew me to the ENIGMA lab. My goal is to pursue graduate school, although I haven’t narrowed down a field of interest quite yet! In my free time I enjoy hiking and spending time in nature with my dog Ranger, photography, and listening to music. 


Jack McArthur

My name is Jack McArthur, I am a junior at Colorado State University studying Psychology pursuing a bachelors. I plan on going to grad school to obtain a masters in social work or a masters in counseling, and possibly a PhD. I am very interested in the upcoming experimental field of Psychedelic assisted therapy and addictions counseling. I am also interested in researching Psychedelics and pursuing a career as a researcher. In my free time I love to hangout with my friends, practice yoga, make music, go to the gym, and play video games.

Lab Alumni


Jesse Ruehrmund, B.S. (she/her)-2021-2024

Tabitha McMichael, B.S. (she/her)-2021-2024

Sam DiCecco, Ph.D. (he/him)- 2021-2024

Bridgette Coughlin, B.S. (she/her)- 2023-2024

Riley Ahern, B.S. (he/him) -2023-2024

Marco Rossi (he/him)-2023-2024

Carter Bruning, B.S. (he/him)-2023-2024

Scout Watson (she/her)- 2023-2024

Cullen Donnelly (he/him)- 2023-2024

Kenyon Perkins, B.S. (she/her)- 2023-2024

Leila Zulic, B.S. (she/her) – 2021-2023

Mikayla Allen (she/her) – 2021-2023

Patrick Gonzalez, B.S. (she/her) – 2021-2023

Dane Roesler, B.S. (he/him) – 2022-2023

Perri Freeman-McKeon, B.S. (she/her) – 2022-2023

Morgan Wright (she/her) – 2023

Mira Urushima, B.S. (she/her) – 2023

Hector Gutierrez, M.S. (he/him) – 2021-2022

Wes MacLean (he/him) – 2021-2022

Taylor Knox, B.S. (she/her)- 2021

Wyatt Taylor (he/him) – 2021

Lindsay McCarron (she/her) – 2021