Does being overweight play a role in the reduced inhibitory control of patients receiving treatment for substance use disorder?

Background: Impaired inhibitory control is present in individuals with substance use disorder (SUD) and in those with obesity. However, the question as to whether patients with SUD who are either overweight or obese have impaired inhibitory control, relative to patients with SUD and normal weight, remains unanswered. Methods: Sixty-two adult men (mean age: 31.17±8.79) under treatment for SUD performed a general and drug-specific inhibitory control test (GoNogo). Participants were divided in two groups based on their BMI. Patients with a BMI higher or equal than ≥25 kg/m² were in the overweight and obese group (OB), and patients with a BMI lower than 25 kg/m² were in the normal weight group (NW). Analyses of covariance (ANCOVA) were performed to explore differences in drug-specific and general commission errors, as well as reaction time for go trials during both drug-specific and general inhibition tasks. Models were adjusted for anxiety, depression, age, and duration of drug use. Results: No differences were found for commission errors in both tasks. With regards to reaction time, no differences were found for the general inhibitory control paradigm, whereas the OB group demonstrated slower reaction time during the drug specific paradigm, relative to the NW group (p=0.03, f² = 0.09; OB: 520.65±71.39 ms vs. NW: 486.07±51.75 ms). Conclusion: Our findings suggest that those undergoing treatment for SUD and are either overweight or obese present impaired inhibitory control when facing drug cues. Future research should explore the effects of physical activity, nutritional counseling, and food monitoring on inhibitory control outcomes in SUD rehabilitation.