"We observed improved mood and optimism," says Zangen. "For example, people who before were just at home doing nothing were able to go back to work."

Brainsway is currently seeking approval in Europe and the United States for deep TMS as a therapeutic tool for depression and other brain-related diseases. Zangen anticipates that the technology will be approved in Europe within the next few months. Before it gains FDA approval, the company will have to test the technology on a much wider population. Zangen's team is now mobilizing clinical trials in a number of medical centers in the United States, including Johns Hopkins University and Harvard Medical School.

Meanwhile, Brainsway is designing different coils to tackle brain regions associated with other conditions, such as post-traumatic stress disorder, autism, and drug addiction. Zangen says that in addition to stimulating underactive areas of the brain such as those associated with depression, deep TMS can be used to inhibit brain regions that may be abnormally overactive, such as during addiction.

"The idea is, you want to reduce some connectivity that was established during addiction, and actually weaken some synapses in the reward system of the brain," says Zangen. "If you use lower-frequency stimulation, you can actually inhibit overactive neurons and reduce connectivity over the long term."

Alvaro Pascual-Leone, director of the Center for Noninvasive Brain Stimulation at the Beth Israel Deaconess Medical Center, says that while deep TMS may have beneficial effects on depression, it may not work for all patients, and researchers will have to find a way to tailor the technology to each individual.

"It's still unclear how to make TMS optimally antidepressant for any one individual," says Pascual-Leone. "Ultimately, you would have to individualize intervention. But this is the only successful attempt in generating a coil that can reach deep in the brain, and that's exciting."