Secondary outcomes and qualitative findings of an open-label feasibility trial of lisdexamfetamine dimesylate for adults with bulimia nervosa.

ABSTRACT

BACKGROUND: There is emerging evidence that stimulants warrant further investigation as a treatment for bulimia nervosa (BN) including a recent open-label feasibility trial examining the use of lisdexamfetamine dimestylate (LDX) for BN. The current report presents the secondary outcomes and qualitative interview results from that feasibility trial. These outcomes explore several purported mechanisms that may explain how stimulants affect symptoms of BN appetite, impulsivity, obsessive and compulsive symptoms, eating disorder psychopathology/impairment and reward-based decision-making. METHODS: Twenty-three participants with BN received LDX for eight weeks. Questionnaires assessing appetite, impulsivity, obsessive and compulsive symptoms, eating disorder psychopathology and impairment were administered at baseline and post-treatment. Participants also completed a two-step reinforcement learning task to assess their decision-making. Semi-structured interviews took place at baseline, week 5, and follow-up. RESULTS: Reductions in hunger, food-related impulsivity, obsessive and compulsive features, eating disorder psychopathology and impairment were found. However, reward learning, as far as it is assessed by the task, did not seem to contribute to the effect of LDX on BN symptoms. Qualitative analysis suggested four themes (1) reprieve from the eating disorder, (2) improvement in function and quality of life, (3) renewed hope for recovery, and (4) ability to normalize eating. CONCLUSIONS: This report suggests several potential mechanisms by which LDX may reduce symptoms of binging and purging in those with BN. Importantly, due to the open-label design, we are unable to attribute findings to the medication. Instead, our results should be interpreted as hypothesis generating to inform future studies such as adequately powered randomized controlled trials. Trial registration NCT03397446.

Recent research suggests that stimulant medications could be a potential treatment for bulimia nervosa (BN). Participants in this study took lisdexamfetamine dimesylate (LDX) for 8 weeks while their eating disorder symptoms and medical status were carefully monitored. As part of this study, twenty-three participants with BN completed several interviews, questionnaires and computer tasks at the start and end of treatment which were delivered to help researchers learn more about the how LDX impacts people with BN. Scores on questionnaires measuring different aspects of the eating disorder improved over time. Participants' performance on the computer task which measures a type of decision making did not change during treatment. Interviews exploring participants' experience taking LDX found four common themes reprieve from the eating disorder, improvement in function and quality of life, renewed hope for recovery, and ability to normalize eating. This report suggests several potential ways LDX may reduce symptoms of binging and purging in those with BN. Importantly, due to the size and type of study, we cannot conclude that changes observed were a direct result of the medication. Instead, our results should be used to form new questions that can be explored by larger studies with controlled designs.