A new study released in October in Molecular Psychiatry explored what the optimal ketamine dose is for its use as an antidepressant. Most studies that have looked at ketamine’s ability to rapidly reduce depressive symptoms and suicidal ideation used 0.5mg/kg over 40 minutes as the target dose, and lower (ex: 0.1mg/kg) or higher (1.0mg/kg) doses had rarely been studied before this article. Researchers at Massachusetts General Hospital and five other US medical centers compared four different doses of intravenous (IV) ketamine among 99 adults in outpatient treatment for treatment-resistant depression. In this study, treatment-resistant depression is defined as “failed to respond satisfactorily (i.e., <50% improvement in depression symptoms) to at least two adequate courses of treatment during their current depressive episode.”
The study showed that the higher dose (1.0mg/kg) was no better than the standard dose (0.5mg/kg) in terms of depressive symptom reduction, but the standard dose was tolerated better with less side effects, dissociative symptoms, and transient high blood pressure. Conversely, the lower dose (0.1mg/kg) was extremely well tolerated but for some patients it was less effective.
This study was good confirmation for providers everywhere that more is not necessarily better. Although each patient needs an individualized treatment plan to best optimize treatment response, the standard ketamine dose of 0.5mg/kg is still the dosage choice when it comes to ensuring efficacy and reducing the risk of unpleasant side effects. In addition, lower doses may be a reasonable treatment option in patients who cannot tolerate 0.5mg/kg.
If you would like to learn more about ketamine treatment for depression, ketamine infusions in New York City, or to schedule an evaluation, please call Principium Psychiatry, located near Columbus Circle in Manhattan, at 212-335-0236.