Trial of Enhanced Neurostimulation for Anorexia

Condition(s) studied

Investigational drug(s) / intervention(s)

MagPro TMS device (ARTG: 204659): rTMS will be administered using a MagPro TMS device (ARTG: 204659) which is approved for its intended use in this trial. rTMS involves the application of transient magnetic pulses which induce small currents in the underlying cortex via the principal of electromagnetic induction. rTMS will be administered using a patterned frequency stimulus called intermittent theta-burst stimulation (iTBS).This form of rTMS was chosen because a recent large multicentre trial showed 3 minutes of iTBS attained the same therapeutic effect as 30 minutes of standard rTMS, leading to FDA approval for depression. Each treatment session will comprise an extended iTBS session, i.e., 6.6 mins, delivered at 100% resting motor threshold (RMT). It will be targeted to the left DLPFC (F3 using the 10-20 International EEG system), consistent with the prior RCT of rTMS for AN.

tDCS mini-CT Stimulator (Soterix, USA: ARTG: 284637): tDCS will be self-administered using the 1x1 tDCS mini-CT Stimulator (Soterix, USA: ARTG: 284637) with two saline-soaked sponge electrodes held in place on the scalp using the Soterix Ole-2 headband. The device is intended to treat different neurological and psychiatric disorders. tDCS involves the passing of weak electrical current through the brain via electrodes placed upon the scalp. The current modulates the resting membrane potential of stimulated neurons which causes changes in neuronal excitability. The anode will be placed over the left F3 (10-20 System) and the cathode over F4 (electrode sizes 5 x 5cm, 25cm2). This montage was chosen to target the left DLPFC, consistent with prior pilot studies of tDCS in AN.

Study summary

Preliminary open-label studies have suggested that non-invasive brain stimulation methods of both transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS) have clinical benefits for improving psychological and eating disorder related symptoms, which can persist at long-term follow ups after acute treatment (i.e., at 6 and 12 months).

Here the investigators propose to conduct the first double-blinded, randomised sham-controlled study to directly compare the therapeutic effectiveness and acceptability of both treatment modalities.

Participants will be recruited and treated at one inpatient setting (Northside Clinic, St Leonards, Sydney). This facility is one of the largest specialist eating disorder settings in Australia with approximately 130 new admissions every year (2019 data). All participants who give consent and who fulfill the eligibility criteria will be randomised to receive active tDCS, sham (placebo) tDCS, active rTMS or sham rTMS over 8 weeks. Trial participants, their treating psychiatrist, ward staff, and a study staff member (who will conduct blinded assessments of mood secondary outcome measures) will be blinded after assignment to intervention until the database is locked and the primary analysis completed. All participants will complete assessments of eating disorder symptoms, mood, psychological symptoms, neurocognition and functioning at baseline, end of week 4, 8 and 20.

Expected outcomes include data on the relative effectiveness and acceptability for both treatment modalities in the inpatient and at-home setting (i.e., for at-home tDCS). The investigators expect that both active treatment arms will produce clinical benefits and have high acceptability, and that clinical benefits will be maintained with long-term at-home tDCS continuation treatment. These outcomes have potential to assist in reducing hospital stay and emergency re-admissions and improving day to day functioning in participants. Health economic data for both treatment modalities will additionally have utility from a service perspective, given the disparity in resource requirements between the two treatments (TMS, tDCS) in terms of costs for patients and access to treatment for people living in remote and rural areas (i.e., for at-home tDCS).

Eligibility

Primary outcome measure(s)

• Effectiveness - Eating Disorder Examination Questionnaire (EDE Q) — Change from baseline at 8 weeks
  Self-report instrument that measures eating disorder behaviors and attitudes. Eating Disorder Examination Questionnaire; 28-items; rating scale 0 - 6; Higher scores on the global scale and subscales indicate more problematic eating behaviours and attitudes.
• Acceptability — 8 weeks
  Number of completed sessions for active tDCS and active rTMS in the acute 8 week RCT period.

Trial sites (1)

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