Abstract: Objective · To investigate the change of response inhibition function in patients with drug-naive bulimia nervosa (BN) and its relationship with eating disorders and self-reporting impulsiveness. Methods · Thirty-five drug-naive BN patients who accepted psychological counseling in Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine between Aug. 2018 and Jun. 2019, and 23 healthy controls (HC) were recruited. The eating disorder and impulsiveness were compared between the two groups by using the Chinese version of Eating Disorder Examination Questionnaire 6.0 (EDE-Q 6.0) and Barrett Impulsiveness Scale-11 (BIS-11), respectively. The stop signal task (SST) was used to assess response inhibition function. The scale scores and SST results were compared between the two groups, and the correlation of stop signal reaction time (SSRT) with BIS-11 score, EDE-Q 6.0 score, the age of onset and the duration of illness was analyzed. Results · Compared with the HC group, the BN group demonstrated significantly longer SSRT in the SST (P=0.003), and had a higher total score of BIS-11 (P=0.004), attentional impulsiveness score (P=0.008) and non-planning impulsiveness score (P=0.002). SSRT was positively associated with the age of onset (r=0.503，P=0.006), negatively associated with the score of weight concern subscale (r=-0.337, P=0.048), and not correlated with the BIS-11 score and the duration of illness in drug-naive BN patients. Conclusion · Drug-naive BN patients have high impulsiveness, and their defects in response inhibition are associated with the age of onset and weight concern.

Key words: bulimia nervosa (BN), response inhibition, stop signal task (SST), inhibitory control, eating disorder