Question

Recent research suggests that ____________, repeated electromagnetic stimulation via a coil placed at the scalp, has been shown to help in the treatment in of depression.

Answer 1

I believe the correct answer is transcranial magnetic stimulation (TMS).
Its definition matches that which you have given us above, as it includes the use of a magnetic field generator, referred to as 'coil,' in order to stimulate certain parts of the brain. The technique is used to treat various types of movement and mental disorders, including depression.