Major depression is a major public health problem, both because of its high incidence (estimated at 15 % of the world population), its comorbidity and the importance of non-response/resistance to drug therapies by antidepressants (about 50 % of patients do not respond to treatments, even when the dose has been optimised and patients are compliant). The objective of this project is to develop a brain stimulation device using a transcranial and focal repeated ultrasonic stimulation technique. Indeed, this technique allows to stimulate, in a focal way, deep regions of the brain, in a non-invasive way, and without impacting the functioning of brain regions located above the focal point. It has already been shown that this stimulation is effective in mice in the treatment of depression, but it is now a question of testing it in large animals, closer to humans with regard to the anatomy of the cranial bone and the brain and elucidating the underlying mechanisms. At the end of this project, the mechanisms engaged in the rodent, the characteristics of stimulation in the non-human primate and its safety will be known. The first clinical trials in humans can be undertaken.