Honors Theses and Capstones
Date Completed
Spring 2026
Abstract
Substance use disorder (SUD) is a major public health concern characterized by compulsive substance use despite adverse consequences. While contemporary models emphasize biological, psychological, and environmental contributors, stress- and reward-related systems are often examined in isolation. This review integrates these systems within an evolutionary mismatch framework to examine how chronic stress exposure and repeated substance use increase vulnerability to addiction. Stress and reward systems are evolutionarily conserved but may become chronically dysregulated under modern conditions characterized by persistent psychosocial stressors and highly potent rewarding stimuli. This is associated with converging neuroadaptations across stress and reward circuitry, resulting in altered affective processing, reduced reward sensitivity, and impaired regulatory control. These changes reflect disruption of stress–reward and executive control interactions under chronic environmental load, promoting negative reinforcement-driven and compulsive behavior that increases susceptibility to substance use and relapse. This framework has implications for informing prevention and treatment.
Document Type
Undergraduate Thesis
First Advisor
David Steinberg
College or School
COLSA
Department or Program
Biological Sciences
Degree Name
Bachelor of Science
Recommended Citation
Castrucci, Nicholas L., "Stress and Reward Interactions in Substance Use Disorder: An Evolutionary Mismatch Framework" (2026). Honors Theses and Capstones. 985.
https://scholars.unh.edu/honors/985
Included in
Biology Commons, Evolution Commons, Neuroscience and Neurobiology Commons, Substance Abuse and Addiction Commons