Ketamine infusion may be as effective as electroconvulsive therapy (ECT) for individuals with treatment-resistant depression who do not have psychosis. Under certain conditions, it even offers fewer side effects. This is one of the conclusions from the largest comparative study conducted to date on the subject, published in the scientific journal The New England Journal of Medicine.
In recent years, ketamine (a medication used as an anesthetic since the 1960s) has gained prominence in the field of mental health. This is because options for relief are limited for those who suffer from treatment-resistant depression, a condition that affects one-third of the 300 million people diagnosed with depression worldwide, according to the World Health Organization. Both ketamine and ECT have shown to be viable options for treating individuals in these conditions.
Currently, ECT treatment is considered painless and safe, but the associated stigma leads to its underutilization. Additionally, some side effects, such as temporary memory loss, muscle pain, or weakness, deter people from undergoing the treatment.
According to Amit Anand, the study’s lead author and a professor of psychiatry at Harvard Medical School, the research, sponsored by the Cleveland Clinic Foundation, shows that ketamine is easier to administer, requires fewer treatment adjustments, and has fewer patient dropouts.
“The results were very surprising to us,” said Anand to The New York Times, explaining that the primary hypothesis was that ketamine and ECT would be at least equivalent, but the anesthetic ended up performing better.
“Most importantly, the study shows that ECT, as expected, is associated with memory problems, while ketamine is not,” Anand added.
The study involved 365 patients who were randomly given ketamine infusions or ECT. While nearly half received ketamine twice a week, the other group underwent ECT treatment three times during the same period. After three weeks, 55% of patients in the ketamine group and 41% of patients in the ECT group reported a 50% or greater reduction in depressive symptoms. After six months, both groups showed similar indicators of quality of life.
A limitation observed in the study was that the number of ECT treatments administered may have been insufficient, as the period was only three weeks. According to Dr. Daniel F. Maixner from the University of Michigan (unrelated to the study), the volunteers started the tests receiving electrical currents on only one side of the brain, which may require 10 to 12 sessions, contrary to the nine used in the study.
As the expert pointed out to NYT, if the patients had undergone more ECT sessions, a higher proportion of them may have responded to the treatment. However, this likely would have caused more side effects.
It is worth noting that ketamine also presents side effects, such as the possibility of dependence. Therefore, it is considered essential that the doses be regulated and the infusions be carried out in a controlled environment with medical supervision before, during, and after the applications.
The next step for Anand and his colleagues is to recruit 1,500 patients for a larger comparative study, involving volunteers with suicidal ideation in addition to depression. The idea is also to observe how the effects differ across age groups and thus seek to offer increasingly safe and effective options for those who do not find relief in available medications.