The serial ketamine TRD-bipolar RCT reports positive acute response but explicitly flags relapse within 2-4 weeks post-infusion, prompting no label expansion for bipolar indication.

A clinical trial testing repeated ketamine infusions for people with bipolar disorder and treatment-resistant depression will report that ketamine does work — patients feel better quickly. But the study will also make clear that the improvement fades within two to four weeks after treatment stops. Because of that durability problem, the FDA (the US Food and Drug Administration, the agency that approves drugs) won't expand ketamine's approved uses to cover bipolar depression. This matters because millions of people with bipolar disorder struggle to find treatments that work.

Ketamine's durability problem is consistent across the literature. As a reviewer, I expect efficacy with a maintenance caveat — insufficient for a bipolar label change absent a dedicated program.