Tuberculosis remains the leading infectious cause of death among people living with human immunodeficiency virus (HIV). An estimated 10.7 million people developed tuberculosis worldwide in 2024, including 619,000 people living with HIV, while tuberculosis caused an estimated 150,000 deaths among people living with HIV. The two epidemics are better understood as a syndemic than as a co-infection because they concentrate in the same populations, interact biologically, and share adverse social conditions. Evidence indicates that integrating tuberculosis and HIV services shortens the time to antiretroviral therapy initiation but has not demonstrated a mortality benefit in meta-analysis or a cluster-randomized trial. Service integration improves coordination within healthcare, but does not address many of the conditions driving the burden outside the clinic. Evidence from India illustrates this gap. In a cluster-randomized trial, household food rations reduced tuberculosis incidence among contacts by about 40%, and the World Health Organization now recommends nutritional support for contacts in food-insecure settings. Prevention therefore needs clinical measures alongside action on undernutrition, housing, income, and access to care.

This Special Issue (SI) is the 13th in an annual series on behavior change, health, and health disparities comprised of invited contributions from speakers at the 2025 Vermont Center on Behavior and Health annual national conference. This year's theme is Contributions of Behavioral Pharmacology and Behavioral Economics to Addiction Science. In addition to this brief introduction, the special issue includes 13 peer-reviewed articles ranging from historical overviews and systematic literature reviews to reports of results from original preclinical and clinical studies. The contributions of behavioral pharmacology and behavioral economics to addiction science are extensive. As such, only selected exemplars are included in this SI. The articles included have considerable breadth, scientific rigor, and clinical importance addressing advances in treatments for opioid, stimulant, and tobacco use disorders, as well as concepts and methods for investigating and characterizing the addiction potential of different drugs, formulations, and an ever-expanding number of commercial products that include psychoactive substances. Collectively, these articles illustrate a history of diverse and impactful contributions from behavioral pharmacology and behavioral economics research to addiction science over more than half a century and a trajectory that holds promise for even more contributions going forward.