Smaller tests have previously indicated it may be effective, but now a large, randomized trial has provided evidence that the drug ketamine may be effective as a treatment for depression. This research looked specifically at the effect of the drug in cases of depression where existing treatments had been ineffective, offering new hope for treatment in the toughest cases. Depending on the results of future research, it may have a notable impact on the future of depression treatment, but as you may expect, this is very unlikely to be in a direct sense. Finding out more about the study gives a much clearer sense of how it may influence future practice.
A piece of research in the American Journal of Psychiatry used a double-blind, randomized approach to determine how effective ketamine is in treatment-resistant cases of depression. They assigned two-thirds of the 73 participants ketamine, and the remaining third were given midazolam, a sedative that served as an active placebo. This means that it is not an inactive sugar medicine. For psychiatric evaluations, they used a depression rating scale to determine the severity of the participants’ depression.
The group receiving ketamine showed greater improvement on the depression rating scale than those receiving midazolam after 24 hours. Of the patients receiving ketamine, 64 percent improved after a day, compared to just 28 percent of those who received midazolam. Although the result after 24 hours was the primary outcome measure (the main thing they were looking for), it’s worth noting that there was no major difference between the scores of the two groups after a week. However, since the participants received only one dose of their assigned medication, it would be expected that there would be little effect remaining so long after receiving the medication.
Ketamine is a dissociative anesthetic drug that is often abused. Therefore, it should come as little surprise that 17 percent of those who received the drug developed dissociative symptoms. Although it’s listed in the paper as a side effect, it’s actually the most well-known effect of the drug, and it disappeared a couple of hours after the initial dosage. However, two patients (about 4 percent) from the ketamine group had to be pulled out of the study because of notable changes in blood pressure when the drug was administered.
As always, with a new piece of research work, more studies are needed to determine whether this effect is genuine or a mere fluke result. Ketamine is a Schedule III controlled substance, which makes researching it a little more difficult and developing drugs based on it a dangerous game, although it is currently used in both animals and humans for anesthesia. As always, treatment with a pharmaceutical for a psychological condition needs to be accompanied by counseling in order to increase its effectiveness, so ketamine (or any drugs based on it) does not constitute the magic bullet for these treatment-resistant cases. It may just become another useful tool in the prescribing physicians’ arsenal for use in notably severe situations.