This study is testing a new medicine called NBI-1070770 to see if it helps people with Major Depressive Disorder (MDD), which is a condition causing long-term sadness and lack of interest in life. The study will compare the effects of NBI-1070770 to a placebo, a pill with no medicine, to make sure any improvements are because of the medicine itself. If you join, you need to have been on your current depression medicine for at least 8 weeks and be ready to keep taking it. You should not be pregnant, have unstable health conditions, or have a history of certain mental health issues. The study will check your health regularly to make sure it's safe.

• The study might require regular visits to check your progress and safety.
• Compensation may be offered for participation.
• Ensure you can follow all the study rules and procedures.