MST for Parkinson's Disease

Inclusion Criteria:

1. Are outpatient or inpatient persons capable of providing informed consent;

2. ≥50 years old;

3. Confirmed diagnosis of Parkinson's disease based on UK Brain Bank criteria;

4. Hoehn and Yahr stage between 1-4;

5. MINI International Neuropsychiatric Interview diagnosis, Version 6 (MINI-6.0.)diagnosis of a current major depressive episode;

6. IDS score of ≥22 (moderate/severe depression);

7. Are on stable doses of psychotropic medication;

8. Are considered to be appropriate to receive convulsive therapy as assessed by anattending psychiatrist and a consultant anaesthesiologist;

9. Patient may or may not be on antidepressant medication, but If on antidepressantmedication, they should be agreeable to keep their current antidepressant treatmentconstant during the intervention;

10. are able to adhere to the intervention schedule;

11. meet the MST safety criteria;

Exclusion Criteria:

1. Current diagnosis of major neurocognitive disorder other than PD (eg. MultipleSystem Atrophy, Lewy Body Dementia) or dementia (Montreal Cognitive Assessment (MoCA) <21)

2. Current active psychosis;

3. Have any of the cardiovascular risk factors listed on the Revised Cardiac Risk IndexScore

4. Unstable medical conditions that, in the opinion of the Principal Investigator,carries significant risk of exacerbation by either of the study interventions;

5. Psychotropic medication initiation <4 weeks prior to enrolment (two classes,antiparkinsonsian and antidepressant compounds);

6. Have an intracranial implant (e.g., aneurysm clips, shunts, stimulators, cochlearimplants, or electrodes) or any other metal object within or near the head,excluding the mouth, that cannot be safely removed;

7. Require a benzodiazepine dose > 2mg/day of lorazepam or equivalent dose or are onany anticonvulsant due to the potential of these medications to limit the efficacyof MST;

8. Are unable to communicate in English fluently enough to complete theneuropsychological tests;

9. Have a non-correctable clinically significant sensory impairment (i.e., cannot hearor see well enough to complete the neuropsychological tests).

10. Have a non-correctable clinically significant sensory impairment (i.e., cannot hearor see well enough to complete the neuropsychological tests).