Faculty, Staff and Student Publications

Publication Date

4-1-2026

Journal

Experimental and Clinical Psychopharmacology

DOI

10.1037/pha0000817

PMID

41396658

PMCID

PMC13138464

PubMedCentral® Posted Date

5-5-2026

PubMedCentral® Full Text Version

Author MSS

Abstract

Fentanyl-related, cocaine-overdose deaths have drastically increased, yet research on how people who use cocaine perceive fentanyl adulteration is limited. This study developed the novel Adulterated Cocaine Purchasing Task (ACocPT), a modification of the original Cocaine Purchasing Task, to quantify how people respond to fentanyl adulteration in cocaine. In the ACocPT, participants indicated how much cocaine they would purchase when cocaine had no (0%) vs. some (10%) probability of fentanyl adulteration. Study aims were: 1) determine how possible fentanyl adulteration affects cocaine demand, and 2) determine which individual characteristics predict continued demand for cocaine despite fentanyl adulteration. This Amazon Mechanical Turk study included self-reported cocaine purchasers (N = 64), who completed self-report questionnaires (demographics, substance use history, depression/PTSD symptoms, fentanyl knowledge quiz), and the ACocPT. Results showed 1) greater probability of fentanyl adulteration (10%) lowered cocaine demand, but only for intensity (Q0; amount of cocaine consumed when free; p < .001); 2) no effect on other demand indices (Omax, Pmax, essential value, breakpoint); 3) significantly more zero-responders with 10% probability of fentanyl adulteration than 0%, p < .001; and 4) opioid co-use, depression, age, PTSD, fentanyl knowledge, and cocaine use severity did not moderate the relationship between fentanyl adulteration and intensity. Overall, fentanyl adulteration reduced cocaine demand but only for volume preferred at minimal cost, not general motivational drive for use, illustrating the dangerous insensitivity to toxic contamination. The internal validity of the paradigm provides proof-of-concept for this approach to identify individuals at risk from fentanyl adulterated cocaine.

Keywords

Fentanyl, Humans, Cocaine, Male, Female, Adult, Drug Contamination, Young Adult, Cocaine-Related Disorders, Middle Aged, Probability, Surveys and Questionnaires, Self Report, cocaine demand, fentanyl, behavioral economics, purchase task

Published Open-Access

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