Most patients with severe depression who used vagus nerve stimulation in a large US trial felt better. Nearly 70% saw positive changes. These patients did not improve with drugs or therapy first. The device sends gentle electric signals to a nerve running from the brain to the gut. It did not cure depression but gave relief that grew stronger over time.
A limited group of patients in Australia tested a similar implant. Their mood improved and held for a long period. Tests with creatine also suggest it might help mood, but scientists say further study is needed before drawing conclusions.