This study will test how well a medicine called AXS-05 works compared to bupropion in stopping depression from coming back in people with major depressive disorder (MDD). In MDD, people feel very sad for a long time. First, everyone in the study takes AXS-05 for 10 weeks to see if they feel better. If they do, they are split into two groups: one continues AXS-05, the other switches to bupropion. This part lasts up to 26 weeks, or until depression returns.

• The study lasts for up to 36 weeks total (10 weeks open-label and 26 weeks double-blind).
• You must have been feeling sad or depressed for at least 4 weeks to join.
• You cannot join if you took part in another AXS-05 study or tried other new treatments recently.

If you join, you might help find a better way to stop depression from coming back. However, there are strict rules about who can take part, and you need to follow study instructions closely. Always talk with your doctor before deciding to join any study.