Researchers at Mayo Clinic have found that the general anesthetic, Ketamine, is very effective at treating depression when administered over a long period.

The study, published in the Journal of Psychopharmacology, revealed that prolonged, low-dose intravenous infusions of Ketamine, have excellent potential in reducing the symptoms of severe depression.

About ten years ago researchers identified that Ketamine has properties that can help alleviate depression. However, given the serious psychiatric side effects of the drug, experts have been looking for the safest ways to use it.

Co-author Timothy Lineberry, M.D., a Mayo Clinic psychiatrist, said:

“It’s surprising both that it works and how rapidly it has effects.It sometimes can work in hours to reduce depressive symptoms and suicidal ideation. Our goal is to begin to determine how the drug can be administered safely in routine treatment.”

A total of 10 patients with either a major depressive disorder or type of bipolar disorder were included in the study. All of the participants failed to respond to anti-depressant medications.

The patients were all treated with low-dose ketamine infusions (0.5 mg/kg total dose), up to twice a week, until their symptoms of depression went away.

Ketamine proved to be very effective at helping the patients recover. In addition, the authors found that ketamine infusions at low rates worked just as well as higher infusion rates.

Dr. Lineberry concluded:

“While patients and clinicians are excited about ketamine’s potential, we know that much more research lies ahead before we know which depressive conditions can be addressed with ketamine safely by clinicians in routine clinical practice.”

The researchers evaluated the side effects of the drug with two different psychiatric scales: “the Young Mania Rating Scale” and the “Brief Psychiatric Rating Scale”.

Eighty percent of the participants showed signs of significant improvement. During the study five patients had no depression symptoms at all, four weeks after the study was completed two of them were still in remission.

Researchers monitored side effects with two psychiatric scales, the Young Mania Rating Scale and the Brief Psychiatric Rating Scale. Eight of 10 patients showed at least 50 percent improvement.

Side effects of the drug included:

  • Brief and limited hallucinations
  • Drowsiness
  • Dizziness

Addressing which patients would benefit the most from this form of treatment will require further investigation and research.

Yale scientists, similarly found that small amounts of the drug ketamine can immediately relieve the symptoms of chronic depression, as well as those of treatment-resistant patients within a few hours.

In addition, another study published in the Archives of General Psychiatry revealed that a single intravenous dose of the anesthetic agent ketamine reduced symptoms of depression within 40 minutes among those with bipolar disorder who have not responded to other treatments.

Written by Joseph Nordqvist