###Human: What should I opt for bipolar depression, Lamotrigine or ketamine infusion therapy? ###Assistant: Hello. I can understand your problem. Ketamine infusion therapy has great roles in depression but regular maintenance treatment is needed and which results in a significant burden on patients. Lamotrigine is the right drug for resistant depression. Even in maintenance treatment, the drug has good roles. So, in my opinion, the drug should be started again from a low dose, and gradually the doses are build-up. Lamotrigine is safe and is free of severe side effects.