Hailed a miracle drug in treating depression, Ketamine is now a drug that researchers fear it might work differently on patients’ brains.
A new study published in the American Journal of Psychiatry shows that the drug’s effect is similar to the one of an opioid like oxycodone or morphine – having the same impact on the brain’s opioid system.
The study authors confirm that the drug is effective in treating depression, but they recommend to limit it because it pulls biological triggers that could cause problems in the future – such as opioid addiction.
Previously, ketamine was believed to only act on the glutamate system in the brain, but this study shows that it doesn’t work like that, explains one of the researchers of the study, Alan Schatzberg (Stanford University School of Medicine, California):
“Before we did the study, I wasn’t sure that ketamine really worked to treat depression. Now I know the drug works, but it doesn’t work like everyone thought it was working.”
Ketamine hasn’t been approved for treatment of depression by the FDA, but some doctors prescribed it as a short-term treatment to fix a patient’s problems, even if its capabilities in treating depressions wasn’t fully understood.
Treating Depression, But Increasing the Opioid Dependence?
The study was conducted on only 12 volunteers that suffered from depression and didn’t find an effective treatment. The participants received two doses of ketamine with a gap of two weeks, when they received the opioid blocker naltrexone and then a placebo.
After the placebo test, symptoms of depression improved, and after the naltrexone test, nothing changed. This suggests that ketamine worked on the brain’s opioid receptors.
Neuroscientist Mark George (Medical University of South Carolina) wrote an editorial on the research, explaining:
“We would hate to treat the depression and suicide epidemics by overusing ketamine, which might perhaps unintentionally grow the third head of opioid dependence.”
Researchers recommend using ketamine as an antidepressant because it is effective, but it should be used with care.
The study has some limitations, though. First of all, it had only a small number of participants, and the research doesn’t prove that ketamine works through the opioid system, but it requires those brain receptors to operate.
Ketamine might just release endorphins in the brain like an opioid, but might not directly act on the opioid receptors. Further research is needed, concluded George:
“With these new findings, we should be cautious about widespread and repeated use of ketamine before further mechanistic testing has been performed to determine whether ketamine is merely another opioid in a novel form.”
Andre Blair s is the lead editor for Advocator.ca. He holds a B.A. in Psychology from the University of Toronto, and a Master of Science in Public Health (M.S.P.H.) from the School of Public Health, Department of Health Administration, at the University of North Carolina at Chapel Hill. Andre specializes in environmental health, but writes on a variety of issues.