This study is for adults with Bipolar I Disorder who are having a major depressive episode (MDE), which is a period of feeling very sad or low. **Bipolar I Disorder** is a mental health condition causing extreme mood swings, including emotional highs (mania) and lows (depression). **LB-102** is an experimental drug being tested against a placebo (a pill with no active medicine) to see how well it works and how safe it is. A person who joins the study will take either LB-102 or placebo every day for 6 weeks. The study is **randomized** which means participants are chosen by chance to receive either the medicine or placebo, and it is **double-blind** meaning neither the participants nor the researchers know who is receiving the actual medicine.

• The study lasts for 6 weeks with daily doses.
• Participants will be randomly assigned to a treatment group.
• Participants must meet specific health and condition criteria to join.