An Open-label, Long-term, Safety and Efficacy Study of Aticaprant as Adjunctive Therapy in Adult and Elderly Participants With Major Depressive Disorder (MDD)

The purpose of this study is to assess the long-term safety and tolerability of aticaprant administered as adjunctive therapy to a current antidepressant (selective serotonin reuptake inhibitor \[SSRI\] or serotonin and norepinephrine reuptake inhibitor \[SNRI\]) in all participants with major depressive disorder (MDD).