Even fewer studies have focused specifically on the treatment of BPAD-DP. In the first of these, Dolberg et al randomized 20 patients to HFL-TMS or placebo [28]. Unfortunately the brief report published provides few experimental details but the active group appeared to do better than the sham group after 2 weeks of treatment. In contrast, in the only other randomized trial, Nahas et al found no difference in response between active HFL-TMS and sham in a study of 23 patients [29]. In this study, there was a response rate of 36% in the active and 33% in the sham group. The authors questioned whether the type of sham coil they used was really in part 'active' due the degree of brain stimulation produced with the coil orientation they applied. The same group followed 7 patients who responded to active rTMS over 12 months providing weekly maintenance rTMS [30]. There appeared to be some degree of benefit of maintenance treatment although this was difficult to quantify due to the open nature of the follow up.