Brain "Pacemaker" Treats Depression

Scientists in Toronto studied six patients who had suffered years of untreatable clinical depression. Four women and two men had electrodes planted deep into their brain to stimulate one of the areas involved in mood control.
Each underwent local anaesthetic before doctors drilled two small holes in their skulls. Then, using magnetic resonance imaging to guide them, doctors inserted two thin electrode wires into the brain area. The other ends of the wires were threaded under the scalp down to the lower neck area.
Next, the patients underwent a general anaesthetic to have a pulse generator implant, the "pacemaker", sewn in under the skin of their chest. The wires were hooked up to this to provide constant brain stimulation.
...All six volunteers reported acute effects once the current was switched on. These included a sudden brightening of the room and a "disappearing of the void".
Prior to treatment the patients had failed to respond to conventional therapy such as electroconvulsive therapy (ECT) or psychotherapy.