In patients with treatment-resistant bipolar disorder, intravenous ketamine (average dose 0.8 mg/kg) significantly reduced depressive symptoms, including inner tension, sleep reduction, and suicidal ideation, over four weeks without triggering manic switches. Fifty-nine patients were treated consecutively, and improvements in Montgomery-Åsberg Depression Rating Scale scores were observed from the second week onward. Adverse events were generally mild to moderate. The findings suggest ketamine can be a well-tolerated option for bipolar depression when carefully monitored, though caution is warranted due to the inherent risk of mood switching in bipolar disorder.
Among 45 patients with treatment-resistant depression treated with intranasal esketamine alongside oral antidepressants in a routine clinic, depression severity scores dropped from an average of 40.0 to 22.9 at four weeks and to 9.70 at 52 weeks, with scores remaining near 9-10 at later follow-ups. Eight patients stopped treatment, mostly due to lack of efficacy or side effects. No manic symptoms emerged, and side-effect ratings were low. The findings suggest sustained symptom improvement and a favorable long-term safety profile for those who continued treatment, though the observational design, concurrent treatments, and survivor bias limit the conclusions.