The aim of this study is to evaluate the safety and efficacy of theta-burst rTMS in patients with major depression. Patients will be randomized to receive ether left-sided intermittent theta-burst rTMS or rigt-sided continuous theta-burst rTMS or sham theta-burst rTMS over two weeks period with an option for an additional two weeks period, depending on treatment response. Clinical assessments will be performed weekly by the Hamilton depression rating scale. In addition, standard neurophysiological assessment of cortical excitability will be done.