Diminished Inhibitory Control in Adolescents with Overweight and/or Substance Use: an ERP Study

Adolescence represents a fundamental stage for interactions between excessive food intake and drug consumption. The association between obesity and drug use is unclear, but inhibitory control has been proposed as a common mechanism. The current study aimed to examine differences in inhibitory control measures in adolescents with overweight and/or substance use. Eighty-five adolescents 15-16 years of age were grouped according to a factorial design as cannabis users (n = 44) versus abstainers (n = 41), and alcohol users (n = 50) versus abstainers (n = 35). Participants were also classified depending on their BMI range as normal weight (n = 47) or overweight (n = 38). To measure inhibitory control, participants completed a Go-Nogo task while their brain activity was registered through electroencephalography, recording the event-related potentials during the task. No behavioral differences were found, but overweight teens exhibited lower P3 amplitudes (for both Go and Nogo conditions) compared with normal-BMI teens, indicating general difficulties in recruiting cognitive resources. Also, alcohol users showed higher Nogo-P3 amplitudes compared with alcohol abstainers, suggesting increased need of inhibitory control effort to achieve a good behavioral performance. Results indicate distinct altered inhibitory control functions in overweight adolescents and alcohol users. These findings suggest that different specific mechanisms of modulation of inhibitory control brain processes are involved in excessive food versus drug consumption, against the notion of food-drug competition. Understanding of associations between excessive food intake and substance use in adolescence will require identification of both common and specific risk factors.