An observational-comparative study, without interfering with the treatment, based on an operationalized interview.

Patients with treatment-resistant depression constitute a significant proportion (even 30%) of patients diagnosed with major depressive disorder (MDD. Since 2014, there have been reports of a potential antidepressant effect of the R-ketamine stereoisomer. At the UCK Department of Psychiatry, a phase 2 clinical trial (2a) has been conducted since 2022 with the use of R-ketamine in the form of an intravenous solution, administered by an infusion pump to patients with drug-resistant depression (sponsor Perception Neuroscience, Inc., protocol PCN-101-21, NCT05414422). The available data from studies indicate a potential treatment-transformative effect of the drug, but do not provide comprehensive information on the long-term effects of treatment in terms of effectiveness, tolerability, and safety of R-ketamine use. The study is cognitive and comparative study, without interfering with the diagnostics, treatment, and rehabilitation. It aims to collect effectiveness and safety observations within 12 months of participation in the PCN-101-21 study, at quarterly intervals (3, 6, 9, 12 months, +/- 4 weeks), with particular emphasis on exacerbations of the underlying disease, hospitalization, correction of psychotropic treatment or functional impairment requiring support from social security authorities. The study does not involve additional diagnostic, therapeutic or rehabilitation goals and is a retrospective analysis performed during a single visit.

Inclusion Criteria:

Expressing informed consent to participate in the study and earlier participation in the PCN-101-21 study on site.

Exclusion Criteria:

Informed consent withdrawal.

Patients participating in the PCN-101-21 study from March 4, 2022, on site.

data repository at site, available on request