689. FEASIBILITY AND PRELIMINARY EFFICACY OF N-ACETYLCYSTEINE FOR LOSS OF CONTROL EATING: AN OPEN LABEL STUDY

Abstract Background Loss of control eating is a core feature of eating disorders such as binge eating disorder and bulimia nervosa. However, there are a lack of effective medications for this maladaptive eating behaviour. The only approved medication for binge eating disorder is a stimulant medication (lisdexamfetamine) which has adverse effects that are poorly tolerated by many patients, leading to high discontinuation rates. N-acetylcysteine (NAC) has been shown to restore impairments in glutamate signalling in the brain and reduce compulsive behaviours. Aims & Objectives The aim of this study was to evaluate the feasibility and preliminary efficacy of NAC for loss of control eating. Method A single site open label study involving community residents in greater Melbourne was conducted between January 2023 and October 2024. A total of 36 participants with loss of control eating were enrolled in the study. Participants received oral NAC medication (2400 mg/day) for 12 weeks. Treatment outcomes were assessed using both retrospective questionnaires and ecological momentary assessment (EMA). The primary outcome was feasibility including recruitment rate, retention rate at week 12, and adherence to medication. The secondary outcome was change in loss of control eating from baseline to week 12. Changes in drivers of eating behaviour as a result of NAC treatment were also explored. Results Recruitment rate was 1.7 participants per month; retention rate was 91% and medication adherence was 93%. Participants reported significant reduction in the frequency and severity of loss of control eating after NAC treatment. Participants showed less food craving, emotional eating, and pre-occupation with food at the end of week 12. Discussion & Conclusions Our data show that delivering a 12-week NAC intervention in people with loss of control eating and conducting behavioural assessments using EMA is feasible. This pilot study provides a rationale for conducting a randomised controlled trial to determine the efficacy of NAC for compulsive eating.