Half the patients also received a nasal spray of esketamine, one of the two molecule components in ketamine, while the others received a placebo.
They found a significant improvement in depression scores and decreased suicidal thoughts in the esketamine group compared to the placebo group at four hours and at 24 hours. "The incidence of attempted suicide in these patients is approximately 20-fold higher than that of the general population", Carla M. Canuso, MD, of Janssen Research & Development, told Healio Psychiatry. After each ketamine (or placebo) administration, the researchers waited for about four hours, then assessed the patient on the Montgomery-Åsberg Depression Rating Scale to track any change in the person's depressive state.
Researchers have previously questioned the safe use of ketamine nasal spray. Ketamine could also help in the starting stages of treatment, since most anti-depressants take four to six weeks to take effect.
The researchers looked at 68 people deemed at imminent risk of suicide, all of whom were treated with anti-depressants or admitted to the hospital.
This study was a proof-of-concept, phase 2, study for esketamine; it must still go through a phase 3 study before possible FDA approval. People who got placebo showed better results after 25 days. Patients who received esketamine showed significantly greater improvement in suicidal thoughts at 4 hours (effect size = 0.67), but not at 24 hours after the first dose (effect size = 0.35) or at day 25 (effect size = 0.29).
Intranasal esketamine was generally well-tolerated, according to the authors. The most common events among those receiving esketamine were nausea, dizziness, dissociation, unpleasant taste and headache. Considering that almost all available antidepressants take days to have an effect, this could mean ketamine has a real future filling a current gap in depression treatment.
"Johnson and Johnson" will explain its company's clinical trial results next month at the American Psychiatric Association Meeting.
"Education of the public and physicians needs to balance both potential benefits and the risk of abuse".
Ketamine, a class B drug, is licensed for medical use as an anaesthetic, but in recent years scientists have become increasingly interested in its use in mental health treatment.
Researchers from the Yale University and Janssen Pharmaceutica conducted the experimental research on antidepressant esketamine, which shows that it can be more effectual to overcome the lengthy treatment with conventional antidepressants that lasts for a number of weeks longer for being completely effective. Please see the full study for all other authors' relevant financial disclosures.