This pilot study will investigate the clinical and neurophysiological effects of repetitive transcranial magnetic stimulation (rTMS) followed by comprehensive behavioral intervention for tics (CBIT) in adult patients with Tourette's Syndrome (TS). Two groups of moderate disease severity will be randomized to receive active or sham rTMS targeted to the supplementary motor area (SMA) followed by eight CBIT sessions. The change in tic frequency and severity (primary outcome) and neurophysiological changes (secondary outcome) will be compared between the two groups. The central hypothesis is that low frequency rTMS will augment the effects of CBIT through favorable priming of the SMA network.