But while the potential benefits are comparable and ketamine is easier to administer than ECT, the addiction risks of long-term ketamine treatments aren’t well established, leading some physicians to urge caution. “It’s a question of risk assessment for each individual patient,” said Boris Heifets, who studies ketamine at Stanford University and was not involved in the new research. “Neither of these things is risk-free, neither is transformative.”
The findings, presented Wednesday at the American Psychiatric Association meeting and published in the New England Journal of Medicine, found intravenous ketamine was “not inferior” to ECT. Patients randomly assigned to take ketamine twice a week for three weeks actually had slightly better results, with 55.4% responding to treatment. That compared to a 41.2% response rate for those who had ECT three times per week over the same period.
The study, with 403 participants, was significantly larger than previous ketamine comparison studies; a meta-analysis of these smaller studies, published last year and focused on major depression rather than treatment-resistant depression, found ECT had better results. But the new paper is both better-powered and arguably focused on sicker patients, only enrolling those with major depression without psychosis who didn’t respond to SSRIs, providing strong evidence of ketamine’s equivalence to ECT. A long-time anesthetic, ketamine has gained popularity in recent years as a treatment for depression.
The implications of the findings are “huge,” said Patrick Oliver, medical director at MindPeace ketamine clinics who has researched the drug as treatment for depression but was not involved in the study. Though it was structured to show “non-inferiority,” he said the data suggest ketamine worked better than ECT.
“I would say hands down that this should change the practice of interventional psychiatry,” said Oliver, bringing ketamine from last to first choice for patients who don’t respond to SSRIs. That said, he added, neither results are great. “We’re at a C-minus.”