Trial of Enhanced Neurostimulation for Anorexia

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 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.