Researchers from Inserm, CNRS, Sorbonne University and doctors from AP-HP at the Brain Institute (ICM) have identified one of the mechanisms of action of ketamine which explains its antidepressant effects. The team tested this innovative treatment, usually used as an anesthetic, in patients suffering from resistant depression of severe intensity. Thanks to ketamine, the latter had an increased ability to overcome the negative beliefs they have regarding themselves and regarding the world – which constitute one of the symptoms of the disease – when positive information was presented to them. These results, published in the journal JAMA Psychiatry, open new therapeutic avenues in the management of mood disorders resistant to antidepressants.