Therapeutic use of transcranial Alternating Current Stimulation for Obsessive Compulsive Disorder

INTERVENTION: Transcranial Alternating Current (tACS) is a form of non‐invasive brain stimulation that delivers a weak electrical current that alternates at a specified frequency back and forth between electrodes. The tACS device in this trial (BrightStim) consists of a purpose‐built handheld battery driven unit that delivers a current controlled voltage across an active and reference electrode. The active and reference electrodes are placed within commercially supplied saline soaked sponges. We have developed this device within our research team to produce the same effects as existing commercial devices but to be programmable in a manner that the research team can preset the conditions of use with no capacity for the patients to alter this or use the device in a manner outside of our research protocol. The device has been certified for use by the Alfred Hospital Bioengineering department. To date, there have been hundreds of studies of tACS, including in people with depression, conducted internationally. There have been no issues or problems reported in these studies over and above the known side effects. The BrightStim stimulator is currently being used in a clinical trial in the prevention of dementia in people with mild cognitive impairment (Alfred Health Ethics Approval 274/18, CTN number CT‐2018‐ CTN‐03008‐1), and has been approved for a clinical trial in depression for young people by Monash Health Human Research Ethics Committee (RES‐18‐0000‐521A). It has also been used in other experimental studies with healthy controls by our research group, and has also been demonstrated to produce effects equivalent to those produced with a widely commercially available device in a structured assessment. No safety or other issues/problems arose in any of these studies. M CONDITION: Mental Health ‐ Anxiety Obsessive compulsive disorder; ; Obsessive compulsive disorder PRIMARY OUTCOME: Change in clinical severity of OCD, as measured by the Yale‐Brown Obsessive Compulsive Scale (YBOCS)[Assessed at baseline, 3‐week, 6‐week and 3‐month follow‐up appointments] SECONDARY OUTCOME: Change in event related potentials (error related negativity and N200) as measured by EEG[EEG recording at baseline and post‐treatment (at 6 weeks)] Change in overall anxiety symptoms as measured by the Beck Anxiety Inventory.[Assessed at baseline, 3‐week, 6‐week and 3‐month follow‐up appointments] Change in overall depressive symptoms as measured by Quick Inventory of Depressive Symptoms – self report[Assessed at baseline, 3‐week, 6‐week and 3‐month follow‐up appointments] Changes in overall cognitive ability, which will be assessed using a battery of cognitive tests (composite outcome). Following are the cognitive tests that will be used: ; Response inhibition – Go/NoGo task ; Working memory – n‐back task ; Selective attention – Auditory selective attention task ; Processing speed – Symbol search[Assessed at baseline, 3‐week, 6‐week and 3‐month follow‐up appointments] INCLUSION CRITERIA: • 18‐65 years of age. • Diagnosis of OCD, in accordance with the Diagnostic and Statistical Manual of Mental Disorders 5th edition (DSM‐5). • Have not initiated new OCD treatment (pharmacological or behavioural) or increased dosage of current psychopharmacological treatment in the past 6 weeks. • Demonstrated capacity to give informed consent.