The research study is being conducted to test whether using high dose spaced theta-burst rTMS (a form of repetitive transcranial magnetic stimulation) produces a significant reduction in depressive symptoms compared with sham. This project will recruit patients aged 18-70 with symptoms of bipolar depression (BPD) who have failed (or not shown signs of improvement) after at least two prior treatments. The null hypothesis is that there will be no difference in reductions in depressive symptoms by the end of a five-day treatment period. The alternative hypothesis is that, compared with sham, active TMS will result in a greater reduction in depressive symptoms by the end of the treatment period.
To facilitate the development of rTMS protocols there is a need for biomarkers that are sensitive to BPD symptom severity and clinical improvement. Previously in our lab, investigators developed biomarkers suitable for depression trials, and these biomarkers are very likely to show sensitivity to BPD, since they are associated with brain regions and functions associated with BPD. As a secondary aim, the investigators will try to identify biomarkers in cortical region associated with BPD, and formulate a statistical model that may be able to predict BPD remission after the treatment. this study will lead to development of new brain stimulation treatment protocols and biomarkers, will aid in treatment selection, and eventually lead to better clinical outcome for patients suffering from BPD.