There have been at least 6 meta-analyses of the antidepressant effects of left PFC rTMS. All but one have shown greater antidepressant effects of 2 weeks of HFL-TMS compared to sham; these included an analysis of 6 reports [13], of 12 studies [14], of 16 studies [15], of 10 studies [16] and a Cochrane review of 14 [17]. The single negative study included only 6 reports with 91 subjects and as such had less power than most of the other meta-analyses. Of the larger studies, Holtzheimer et al reported a weighted mean effect size of 0.81 [14], Burt et al reported an effect size of 0.67 [15] and Kozel at al an effect size of 0.53 [16]. These are moderate to large effects. However, the studies repeatedly report that the overall clinical results observed were not that impressive. For example, a mean overall improvement of only 23.8% on the HAMD in the blinded studies reviewed in [14] compared to 7.3% in the sham group.