 TRD is clearly a major health issue - depression is common, results in marked morbidity and mortality and a large percentage of patients do not respond to, or cannot tolerate standard treatment. The development of new treatments for this condition is undoubtedly required. International efforts are underway to try and establish the efficacy of HFL-TMS to the point where the technique may be approved by regulatory authorities and clinically introduced. However, clearly the response rate to HFL-TMS is suboptimal for its widespread use. 