Phenomenological Explorations of the Esketamine-Induced Transient Dissociative State

Patients will be identified when they come for an Esketamine session performed as part of routine practice in the Psychiatry Department of Hôpital Sainte Musse. The clinician, who is also the study investigator, will then select patients who meet the protocol's inclusion criteria and inform them of the research before administering the Esketamine. He will explain the study in detail and give them the information letter.

Patients will then be seen again in consultation outside the Esketamine sessions, as part of routine practice, within a minimum of 48 hours. During this consultation, the investigating physician will obtain their oral consent to their participation in the research, resulting in a research consultation lasting around 45 minutes and including :

• an audio recording of an Experiential Phenomenological Interview;
• completion of the EQFC "Trait" questionnaire.

Inclusion criteria

• Patient followed in the Psychiatry Department of Hôpital Sainte Musse, with depressive state characterized by the DSM-V criteria and treated with Esketamine between 2 days and 3 months prior to the study;
• Patient over the age of 18;
• Patient presented transient dissociative state during Esketamine treatment;
• Patient able to express his/her consent prior to participation in the study;
• Patient who understands and speaks French.

Exclusion criteria

• Patient with major anxiety and panic attack during an Esketamine-induced dissociative state, regardless of Esketamine effect;
• Patient under judicial protection (guardianship, curatorship...) or safeguard of justice;
• Pregnant, parturient or breast-feeding women;
• Any other reason that, in the opinion of the investigator, would interfere with the evaluation of the study objectives.