From the Guidelines
Ketamine infusions are a viable treatment option for patients with treatment-resistant depression (TRD) who have failed at least two previous adequate trials of antidepressant medications. According to the 2022 U.S. Department of Veterans Affairs and U.S. Department of Defense clinical practice guideline 1, ketamine infusion has been shown to improve depressive symptoms in patients with TRD. The guideline suggests that ketamine can be used as monotherapy or in conjunction with an antidepressant, resulting in significant improvement in depressive symptoms after 24 hours, with effects persisting for up to 7 days when used as an adjunctive treatment.
Key points to consider when using ketamine infusions for TRD include:
- A typical ketamine infusion protocol involves administering a subanesthetic dose of 0.5 mg/kg delivered intravenously over 40 minutes, usually twice weekly for 2-3 weeks for the initial series 1.
- Patients may experience dissociative effects, altered perception, or mild hallucinations that resolve shortly after the infusion ends, as well as side effects such as nausea and dizziness.
- Treatment should be conducted in a controlled medical setting with vital sign monitoring, as ketamine can temporarily increase blood pressure and heart rate.
- The antidepressant effect typically lasts 1-2 weeks, so maintenance treatments are often necessary, usually at decreasing frequency (monthly or as needed) 1.
- Ketamine works differently from traditional antidepressants by rapidly increasing glutamate transmission and promoting synaptogenesis and neuroplasticity, particularly in brain regions affected by chronic stress and depression.
It is essential to note that ketamine infusions should only be administered by a qualified healthcare professional in a controlled medical setting, and patients should be closely monitored for potential side effects and suicidal ideation. Additionally, the cost of ketamine infusions, ranging from $400-800 per infusion, is an important consideration for patients. Overall, ketamine infusions offer a promising treatment option for patients with TRD, but should be used in conjunction with other therapies and under close medical supervision.
From the Research
Ketamine Infusions for Treatment-Resistant Depression
- Ketamine infusions have been shown to have rapid yet transient antidepressant effects in patients with treatment-resistant depression, which may be prolonged by repeated administration 2.
- A single ketamine infusion can elicit a significantly greater reduction in depressive symptoms compared to an active placebo control, with cumulative antidepressant effects observed with repeated infusions 2.
- Repeated ketamine infusions have been found to have cumulative and sustained antidepressant effects, with reductions in depressive symptoms maintained among responders through once-weekly infusions 2, 3.
Administration Strategies
- Different administration strategies have been explored, including single infusions, repeated infusions, and maintenance infusions, with varying response rates and durations of response observed 2, 4, 5.
- The optimal number and frequency of infusions remains unclear, with some studies suggesting that two infusions in the first week may improve antidepressant effects compared to a single infusion 5.
- The use of ketamine in combination with other treatments, such as electroconvulsive therapy, has also been explored, with potential benefits in terms of improved seizure quality and reduced post-therapy cognitive impairment 6.
Clinical Effectiveness
- Ketamine infusions have been found to be effective in reducing symptoms of depression, suicidal ideation, and anxiety in patients with treatment-resistant depression, with response rates and remission rates comparable to those observed with other interventional treatments 3.
- The clinical effectiveness of ketamine infusions has been demonstrated in both randomized controlled trials and real-world clinical samples, with significant improvements in depressive symptoms and quality of life observed 2, 3, 4.
- Further research is needed to fully understand the mechanisms of action of ketamine and to optimize its use in clinical practice, including the development of novel administration strategies and the identification of predictors of response 2, 6.