St. Jude Medical said Monday it received U.S. regulatory approval to expand study of a pacemaker-like device that uses electronic signals to treat depression.
The Food and Drug Administration granted the device maker permission to enroll 125 patients at 20 sites across the U.S. Previously the study was limited to three locations.
The study is examining the safety and effectiveness of stimulating a certain area of the brain to treat severe depression. Patients must have depression that has been resistant to four types of treatment, such as drug therapy and electroshock treatment.
Shaped like a pacemaker, the Libra device is implanted under the skin of the chest and then connected to electrodes in the brain. The electrodes deliver pulses of electricity that stimulate the deep brain.
Competitor Cyberonics Inc. already markets a similar device for depression, and comparable implants have been used since the 1990s to treat movement disorders like Parkinson's disease and tremors.
Shares of St. Jude Medical Inc. fell 81 cents to $46.68 in morning trading.