A low-cost version of ketamine has shown promising results in a double-blind trial comparing it to a placebo for the treatment of severe depression, according to research published in the British Journal of Psychiatry. Led by UNSW Sydney and the affiliated Black Dog Institute, the study found that more than 20% of participants achieved total remission from their symptoms after a month of bi-weekly injections, while a third experienced at least a 50% improvement in their symptoms.
The study, funded by the Australian National Health and Medical Research Council, involved collaboration between six academic clinical mood disorder units in Australia and one in New Zealand. Lead researcher Professor Colleen Loo stated that achieving a 20% remission rate is significant for people with treatment-resistant depression, who have not benefited from other therapeutic approaches such as talk therapy or commonly prescribed antidepressants. The study provided definitive evidence of ketamine’s effectiveness by demonstrating a substantial difference in remission rates compared to the placebo group, with 20% of participants no longer experiencing clinical depression compared to only 2% in the placebo group.Â
The trial involved 179 individuals with treatment-resistant depression who were given either a generic form of ketamine or a placebo injection. The generic ketamine used in the trial is already widely available in Australia for anesthesia and sedation purposes. The participants received two injections per week in a monitored clinic setting, and the treatment lasted for a month. The study employed a double-blind design to minimize psychological biases, ensuring that neither the participants nor the researchers administering the drug were aware of which patients received ketamine or the placebo.Â
Unlike previous studies that used a saline placebo, this trial used midazolam, a sedative that causes mild sedation, to improve treatment masking. This choice helped prevent participants from discerning whether they received ketamine, as both ketamine and midazolam have acute sedative effects. The trial also included individuals who had previously undergone electroconvulsive therapy (ECT), which is a recommended treatment for depression when other approaches have been ineffective. Most studies exclude individuals who have received ECT due to the challenges of introducing a new treatment in such cases.Â
Notably, the recent trial delivered the drug subcutaneously (injected into the skin) instead of through intravenous drip, reducing both time and medical complexity. Additionally, it is the largest study to date comparing generic ketamine to a placebo for the treatment of severe depression. One of the significant advantages of using generic ketamine for treatment-resistant depression is its affordability compared to the patented S-ketamine nasal spray currently in use in Australia. While S-ketamine costs approximately $800 per dose, generic ketamine is significantly cheaper, with prices as low as $5, depending on the supplier and whether the hospital buys it wholesale.
In addition to the drug cost, patients are responsible for paying for the medical care during the treatment sessions. At Black Dog Institute clinics, this cost amounts to $350 per session. Professor Loo emphasized the need for a Medicare item number to fund this treatment, as it has proven to be powerful and cost-effective. Many patients with severe depression may spend months in the hospital, be unable to work, and experience suicidal thoughts. By providing an effective and rapid treatment like ketamine, individuals can return to work or study and leave the hospital within a matter of weeks.Â
The researchers plan to conduct larger trials of generic ketamine over longer periods to further evaluate its effectiveness and refine safety monitoring protocols. By making this treatment more accessible and affordable, it has the potential to provide relief for individuals suffering from severe depression who have not responded to other treatments.Â
