What is it about?
This study examines whether melancholic features affect how well a single low-dose ketamine infusion (0.5 mg/kg) reduces suicidal thoughts in people with treatment-resistant depression and severe suicidal ideation (TRD-SI). Ketamine is known to rapidly reduce suicidality, but it is not yet clear whether people with melancholic depression benefit in the same way as others. In particular, this study explores whether ketamine affects negative suicidal thoughts differently from positive thoughts such as hope, confidence, and the desire to live.
Why is it important?
Understanding these difference is important because with melancholic treatment-resistant depression often experience more severe symptoms, face a higher risk of suicide, and repond less well with structure treatments. Identify whether melancholic features influence ketamine's effects could help clinicians better personalize treatment and imporve strategies to reduce suicide risk.
Main findings
- Patients without melancholic features showed clear and sustained reductions in suicidal thoughts after ketamine.
- Patients with melancholic features did not show meaningful reductions in negative suicidal thoughts.
- However, melancholic patients showed a brief increase in positive or protective thoughts (such as hope) shortly after treatment, which was not sustained.
What do the authors argue?
The authors argue that ketamine’s antisuicidal benefits depend on depression subtype: patients without melancholic features show clear reductions in suicidal thoughts, while patients with melancholic features experience only a brief increase in positive or protective ideation, suggesting a resilience-enhancing—but limited—effect.
Team Member Spotlight
You can find the paper here.