الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Major depression is one of the most common psychiatric disorders. It is estimated that by 2020 major depression disorder (MDD) will be the 2nd most disabling condition in the world. Despite the availability of a wide array of antidepressant medications, along with electroconvulsive therapy (ECT) and psychotherapy, close to 20% of these patients are refractory to any antidepressant medication. Advances in science and technology offer novel techniques for focally stimulating the brain that might possibly achieve antidepressant efficacy equivalent to that seen with ECT. These techniques include transcranial magnetic stimulation (TMS), vagus-nerve stimulation (VNS), and deep-brain stimulation (DBS). Transcranial magnetic stimulation (TMS) is non invasive technique used to interfere with the function of small cortical areas, through currents induced by alternating magnetic fields arise from a handheld coil placed directly above the targeted area. TMS has been studied in psychiatry mainly for assessment of its putative therapeutic effects in treatment of refractory major depression. Vagus nerve stimulation (VNS) is a surgical procedure that involves placing a subcutaneous pulse generator in the chest wall and electrodes over the left vagus nerve. VNS seems to be a good alternative long-term treatment especially for TRD patients, as they are able to maintain the benefit for at least 21 months. Deep brain stimulation (DBS) involves the placement of electrodes in specified brain regions so that electrical stimulation can be delivered in a targeted manner. The use of DBS is a promising emerging therapeutic modality for selected individuals with treatment resistant depression (TRD).