There are already recently published data on the tolerability and efficacy of the combination of ketamine and/or esketamine with MAOIs. However, these reports are few and far between, and to our knowledge, there are no data involving intranasal esketamine.

Given the numerous interactions between MAOIs and other antidepressants, and the impossibility of combination, this pharmacological class is neglected. This is despite the fact that MAOIs are the only truly tri-aminergic drugs, that they have unparalleled efficacy in certain forms of resistant apathetic depression, and that new, more dietary permissive forms have appeared on the market. The arrival of antidepressants that can be combined with MAOIs, such as ketamine and esketamine, changes the situation and could offer a new treatment opportunity to many patients in a therapeutic impasse. For these opportunities to become a reality, sharing the clinical experience gained by specialized centers is essential.

Inclusion criteria:

• Major subject.
• Having been treated with intranasal esketamine between 01/01/2018 and 01/03/2022.
• Not objecting to the reuse of their data for scientific research purposes.

Exclusion Criteria:

- Subject who has expressed opposition to the reuse of their data for scientific research purposes.

Major subject.having been treated with intranasal esketamine between 01/01/2018 and 01/03/2022.