Dissertation Defense: Recovery Outcomes and Temporal Correlates in Individuals with Polysubstance Use
Dissertation Defense: Recovery Outcomes and Temporal Correlates in Individuals with Polysubstance Use
Fatima Quddos
Graduate Student, Translational Biology, Medicine, and Health
Graduate Research Assistant, Bickel Lab, Fralin Biomedical Research Institute at VTC
May 6, 2025, at 9:30 a.m.
Room R3012, 2 Riverside Circle
About this Dissertation
Polysubstance use disorder (polySUD) presents a significant challenge in the field of addicition due to its high prevalence, variability in recovery trajectories, and poorer treatment outcomes. This dissertation introduces and validates a novel construct—proportion of remission (PrR)—as a continuous measure that captures nuanced recovery progress in individuals with polySUD. Study 1 utilized data from a remote sample of 2,406 individuals with polySUD to examine the association between PrR and Quality of Life (QoL) across four domains: physical, psychological, social, and environmental. Results indicated that higher PrR was significantly associated with improved QoL in all domains, suggesting that PrR offers a granular metric for evaluating recovery outcomes. Study 2 extended this work by exploring how PrR relates to behavioral and recovery-specific variables, including delay discounting (DD), maximum time in recovery, and quit time across substances. Findings demonstrated that longer quit time and reduced discounting rates significantly predicted higher PrR, with a moderated mediation model showing that quit time mediated the relationship between recovery duration and PrR depending on DD levels. Study 3 evaluated the Proximity to Future Index (PTFI)—a non-monetary proxy for temporal window—as an alternative to DD. Results showed that PTFI and DD independently predicted recovery outcomes, including QoL and remission, highlighting the relevance of temporal cognition in recovery science. Collectively, these studies support the clinical utility of PrR as a continuous, person-centered indicator of recovery from polySUD and underscore the potential of temporal window measures like DD and PTFI in understanding and enhancing recovery trajectories.
More About the Candidate and Project
Education
Virginia Tech, Translational Biology, Medicine, and Health, Ph.D. Candidate
William & Mary, M.S., Biology
Training
Graduate Research Assistant, Bickel Lab, Fralin Biomedical Research Institute at VTC
Mentors
The late Warrren Bickel, Ph.D., Professor and Director, Addiction Recovery Research Center and the Center for Health Behaviors Research, Fralin Biomedical Research Institute at VTC
Allison Tegge, Ph.D., Research Associate Professor, Addiction Recovery Research Center, Fralin Biomedical Research Institute at VTC
Committee Members
- Anita Kablinger, Ph.D., Professor and Director of Clinicial Research, Psychiatry and Behavioral Medicine, Virginia Tech Carilion School of Medicine
- Stephen LaConte, Ph.D., Professor and Interim Co-director, Addiction Recovery Research Center, Fralin Biomedical Research Institute at VTC
- Jeff Stein, Ph.D., Assistant Professor, Interim Co-director, Center for Health Behaviors Research, Fralin Biomedical Research Institute at VTC
Quddos F, Fontes R., Dwyer, C. L., Bickel W., Tegge A. (2025). Celebrating each success in the recovery journey; Proportion of remission as a novel measure of recovery from polysubstance use disorder. JAMA network open (Submitted).
Bickel W., Fontes R., Nist A., Nusair G., Quddos F., Bovo C., Cabral, D. A. R., Freitas-Lemos R. (2025). Episodic Future Thinking as a Trans-disease Intervention for Promoting Health-Behaviors: A Critical Review. Health Psychology and Behavioral Medicine (Under review).
Cabral, D. A. R., Tegge, A. N., Dwyer, C. L., Quddos, F., Kaur, R. P., Nguyen, J., Athamneh, L., & Bickel, W. K. (2024). Associations between Delay Discounting and Unhealthy Behaviors in Substance Use Recovery. Drug and Alcohol Dependence, 262(111395), 111395.https://doi.org/10.1016/j.drugalcdep.2024.111395
Quddos F, Hubshman Z, Tegge A, et al. Semaglutide and Tirzepatide reduce alcohol consumption in individuals with obesity. Sci Rep. 2023;13(1):20998. doi:10.1038/s41598-023-48267-2
Bickel W., Freitas-Lemos R., Myslowski J., Quddos F., Fontes R., Barbosa-França B., Faubion-Trejo R., LaConte S (2023). Episodic Future Thinking as a Promising Intervention for Substance Use Disorders: A Reinforcer Pathology Perspective. Current Addiction Reports, doi: https://doi.org/10.1007/s40429-023-00498-z
Fatima Quddos, Devin Tomlinson, Kirstin Gatchalian, Warren Bickel; June, 2023. Comparison Between Original and Adaptive Form of Cocaine Purchase Task. The College of Problems on Drug Dependence, Denver, CO.
Jalil, M., Quddos, F., Anwer, F., Nasir, S., Rahman, A., Alharbi, M., Alshammari, A., Alshammari, H. K., & Ali, A. (2022). Comparative Pan-Genomic Analysis Revealed an Improved Multi-Locus Sequence Typing Scheme for Staphylococcus aureus. Genes, 13(11), Article 11. https://doi.org/10.3390/genes13112160
Quddos, F., & Zwollo, P. (2021). A BCWD-Resistant line of rainbow trout is less sensitive to cortisol implant-induced changes in IgM response as compared to a susceptible (control) line. Developmental & Comparative Immunology, 116, 103921. https://doi.org/10.1016/j.dci.2020.103921
Zwollo, P., Quddos, F., Bagdassarian, C., Seeley, M. E., Hale, R. C., & Abderhalden, L. (2021). Polystyrene microplastics reduce abundance of developing B cells in rainbow trout (Oncorhynchus mykiss) primary cultures. Fish & Shellfish Immunology, 114, 102–111. https://doi.org/10.1016/j.fsi.2021.04.014
Quddos, F., The effect of slow-release cortisol implant on humoral immune responses and infection prevalence following experimental challenge with Flavobacterium psycrophilum in rainbow trout (Oncorhynchus mykiss), Poster presentation at Annual Biomedical Research Conference for Minority Students, 2019