AbstractBackground: Recent neurobiological insights gained from functional neuroimaging studies suggest that bulimia nervosa (BN) is underpinned by dysregulated frontostriatal circuitry, which supports self-regulatory control and food reward processing capacities. Brain-directed interventions may therefore hold promise as treatments for the disorder. The overarching aim of this research was to investigate the therapeutic utility of transcranial direct current stimulation (tDCS; a form of non-invasive brain stimulation) in patients with BN.
Methods: Four studies were conducted: (1) a systematic review of the clinical efficacy of tDCS across all psychiatric disorders; (2) a randomised controlled trial (RCT) of single-session tDCS applied to the dorsolateral prefrontal cortex (DLPFC) in healthy individuals with frequent food cravings; (3) a cross-sectional study of temporal discounting (a marker of poor self-regulatory control) in patients with BN and healthy controls; and (4) an RCT of single-session tDCS applied to the DLPFC in BN.
Results: The main findings were as follows: (1) existing data indicate that tDCS interventions comprising multiple sessions can ameliorate symptoms of several major psychiatric disorders, both acutely and in the long-term; (2) a single session of sham-controlled DLPFC tDCS transiently suppressed craving for sweet foods (i.e., altered food reward processing) among individuals with frequent food cravings; (3) patients with BN showed greater temporal discounting (i.e., poorer self-regulatory control) relative to healthy participants; and (4) a single session of sham-controlled DLPFC tDCS temporarily reduced symptoms, improved mood, and lowered temporal discounting (i.e., increased self-regulatory control) in individuals with BN. Conclusions: Taken together, the results provide preliminary support for the therapeutic utility of tDCS over the DLPFC in BN, and offer justification for multi-session trials in this patient population.
|Date of Award||2017|
|Supervisor||Ulrike Schmidt (Supervisor) & Iain Campbell (Supervisor)|