In the Journals

Brain stimulation may improve bulimia nervosa

Transcranial direct current stimulation briefly improved symptoms of bulimia nervosa in adults, according to recent findings.

“Noninvasive brain stimulation enables targeted manipulation of cortical excitability, and may be useful for ‘normalizing’ altered neural circuit activity in bulimia nervosa,” Maria Kekic, PhD, of King’s College London, and colleagues wrote. “The most common noninvasive brain stimulation modalities are repetitive transcranial magnetic stimulation and transcranial direct current stimulation. Repetitive TMS uses a coil to generate a magnetic field, which penetrates the skull and induces an electrical current, whereas transcranial direct current stimulation delivers a low-amplitude direct current via two surface electrodes (anode and cathode). Although both methods are well-tolerated and have minimal side effects, transcranial direct current stimulation has several practical advantages over repetitive TMS: it is portable, inexpensive, has a more favorable safety-feasibility profile, and can be applied bilaterally.”

To assess efficacy of transcranial direct current stimulation for bulimia nervosa, researchers conducted a double-blind, sham-controlled, proof-of-principle trial among 39 adults with bulimia nervosa. Study participants received three sessions of transcranial direct current stimulation in a randomized fashion: anode right/cathode left, anode left/cathode right, and sham. Psychological and neurocognitive measures were conducted before and after each session and bulimia nervosa symptoms were assessed during the following 24 hours.

Anode right/cathode left transcranial direct current stimulation reduced eating disorder cognitions, compared with anode left/cathode right and sham transcranial direct current stimulation.

Both anode right/cathode left and anode left/cathode right transcranial direct current stimulation reduced the urge to binge-eat and increased self-regulatory control during a temporal discounting task.

Participants exhibited greater mood improvement after anode right/cathode left and anode left/cathode right transcranial direct current stimulation, compared with sham.

All three interventions had comparable effects on wanting/liking food and bulimia nervosa symptoms during the 24 hours after stimulation.

“Our study suggests that a noninvasive brain stimulation technique suppresses the urge to binge eat and reduces the severity of other common symptoms in people with bulimia nervosa, at least temporarily. We think it does this by improving cognitive control over compulsive features of the disorder,” Kekic said in a press release. “Although these are modest, early findings, there is a clear improvement in symptoms and decision-making abilities following just one session of transcranial direct current stimulation. With a larger sample and multiple sessions of treatment over a longer period of time, it is likely that the effects would be even stronger. This is something we’re now looking to explore in future studies.” – by Amanda Oldt

Disclosure: The researchers report no relevant financial disclosures.