Approximately, two-thirds of those treated with Repetitive Transcranial Magnetic Stimulation (rTMS) will not respond adequately. Currently, predicting poor response to this treatment is a challenge. Analysis of the genome of rTMS-treated patients may identify biomarkers useful to predict rTMS response. As such, we are undertaking the first genome-wide association study (GWAS) of rTMS response in an open-label study of routine rTMS treatment.

rTMS is one of the most rapid and effective treatments for patients with major depressive disorder (MDD). rTMS is a novel non-invasive neurostimulation treatment that is effective in the treatment of major depression, and has a very favourable tolerability profile. It involves generating magnetic fields outside of the body to induce a current and to change the firing of neurons in the brain. However, as with other treatments, not all patients experience clinical benefit. As such, the identification of patient-centred markers of response would be of great value to rTMS treatment delivery.

Study Aims:

The objective of this proposal is to identify genetic variants that could be used to pre-emptively detect individuals most likely to respond to or experience side effects from rTMS. To achieve this objective, two aims are proposed.

Aim 1: To compare the frequency of single nucleotide polymorphisms (SNPs) in responders to non-responders in MDD participants treated with rTMS.

Aim 2: To explore the combination of specific historical, demographic, clinical, rTMS parameter, and genomic variables on response to rTMS.

Investigator Team:

Dr. Chad Bousman PhD, Departments of Medical Genetics, Physiology and Pharmacology, and Psychiatry, University of Calgary, Calgary, Alberta

Dr. Alexander McGirr MD, Department of Psychiatry, University of Calgary, Calgary, Alberta

Dr. Scott Patten MD, PHD, Departments of Community Health Sciences and Psychiatry, University of Calgary, Calgary, Alberta

Study Coordinator:

Anita Oomen, BSc