Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

Stacey C. Sigmon


Aims: Opioid use disorder (OUD) is associated with significant morbidity and mortality, and opioid agonist treatment (OAT) with methadone or buprenorphine represents the most efficacious treatment. However, data suggest that chronic administration of opioids may be associated with significant weight gain, possibly by altering an organism’s perception of and preference for sweet foods. The primary aim of this laboratory study was to rigorously examine sucrose subjective response among adults receiving OAT and a comparison sample without OUD. As secondary outcomes, we also sought to compare the groups on additional baseline characteristics that may influence subjective sucrose response and weight gain during treatment.

Methods: Participants were 40 adults receiving treatment for OUD (OUD+) and a comparison sample of 40 adults without OUD (OUD-). All participants completed an initial screening visit that included questionnaires on eating behaviors, diet and nutrition, recent substance use, and measurement of body mass index. Eligible participants completed two, same-day outpatient laboratory sessions during which they sampled six experimenter-administered concentrations of sucrose solution (0, 0.1, 0.25, 0.5, 0.75, and 1.0M in distilled water) each three times under double-blind counterbalanced conditions. Following each exposure, participants rated the pleasantness and intensity of each sample using 100-point visual analog scales.

Results: OUD+ participants rated sucrose solutions as less pleasant than OUD- participants (p<0.001). However, this effect was limited to the three lowest sucrose concentrations (0, 0.1, 0.25M), and at higher concentrations there were no group differences. There were no between-group differences on ratings of intensity (p=0.35). Given these baseline group differences in placebo (0M) responding, sucrose response was also examined in terms of change from baseline. In this analysis, there was a significant group effect, with a higher magnitude of change in pleasantness ratings and a lower magnitude of change in intensity ratings from 0M in OUD+ vs. OUD- participants (p’s<0.05). With regard to baseline characteristics that may influence sucrose response and eating behavior more generally, the OUD+ group had a higher prevalence of obesity, food insecurity, unhealthy eating behaviors, high sugar consumption, and nutrition knowledge deficits compared to the OUD- group (p’s<0.05).

Conclusion: Data from preclinical and clinical research have suggested that opioid agonist medications may enhance subjective response to sweet flavors. In the present study, OUD+ participants exhibited a higher magnitude of change in pleasantness ratings from placebo compared to OUD- participants. However, this effect was largely driven by pronounced group differences in perceived pleasantness of essentially unsweet solutions. On the outcome of sucrose intensity, findings were more mixed with no consistent differences between OUD+ and OUD- participants. In contrast, group differences were far more pronounced in participants’ daily eating behaviors and nutrition knowledge, with OUD+ participants presenting with a consistently more severe profile. These data highlight the significant risk factors experienced by OUD+ individuals that extend beyond drug-related risks and may inform future scientific and clinical efforts to improve health outcomes in this vulnerable population.



Number of Pages

66 p.