"Doctors have successfully treated a woman with severe depression using a groundbreaking 'neural pacemaker' device that detects and resets negative brain activity."

"The device can recognise the pattern of electrical activity in the brain that gives rise to depressive thoughts. It then intervenes by delivering a tiny targeted electrical pulse via an implant.... The treatment involves placing an implant under the skull with electrodes travelling deep into the brain.... The system was tailored to Sarah with the researchers first monitoring her brain activity for a week while asking her to describe her mood regularly. An algorithm was used to identify a pattern of activity in the amygdala region of the brain that corresponded with her worst depressive symptoms. The researchers then located another area of her brain, the ventral striatum, where a very small, six-second pulse of electricity produces a near-instantaneous result. The device intervenes like this about 300 times each day. The only sensation, Sarah said, was a slight feeling of alertness."

From "'The first time I smiled in years': brain implant offers hope to millions with severe depression/'Neural pacemaker' resets negative thoughts" (London Times).