A study undertaken over a five-year period has shown that a single dose of ketamine improved thinking and reasoning in people who had expressed thoughts of suicide within 24 hours.
Carried out by Columbia University, the study found that a single dose of ketamine reduced depression severity in people with suicidal ideation. Many of these individuals had not responded to other antidepressants.
The researchers wanted to better understand the mechanisms behind the rapid anti-depressant effect of ketamine and decided to examine the drug’s impact on neurocognitive performance.
The findings, published in the Journal of Clinical Psychiatry, demonstrated that ketamine made participants feel safer and less likely to harm themselves. Participants who responded positively to the ketamine treatment continued to do well for up to six weeks after they were given an initial infusion in conjunction with other antidepressants that were tailored to the needs of each specific patient.
J. John Mann, MD, senior author and the Paul Janssen professor of translational neuroscience at Columbia University, commented: “We found that suicidal ideation is not just related simply to severity of depression. There are other reasons, including cognitive improvements that are related to a decline in suicidal ideation and thereby make those who are suicidal safer.”
For the research, the team followed 78 participants suffering from major depressive disorder (MDD) and clinically significant suicidal ideation and found that a standard dose of ketamine given intravenously produced a rapid reduction of suicidal thoughts in some individuals.
The team said part of this improvement was correlated with an improvement in problem-solving and thinking more clearly, and highlight that the improvement in neurocognition and suicidal ideation occurred even when some of these individuals did not show comparable improvement in depressive symptoms.
Ravi Shah, MD, chief innovation officer at Columbia Psychiatry said: “Our study helped us gain a better understanding of how ketamine works in the brain and how quickly it can improve distorted thinking. Being able to think more clearly can make someone feel less suicidal.”
The study compared the effects of intravenously administered ketamine to midazolam, a sedative prescribed for anxiety and depression, finding greater cognitive improvements in thinking and reasoning in those who were given ketamine.
The researchers commented that ketamine is evidently changing functioning of important neurotransmitter systems in many key areas of the brain, and further study of the substance and other drugs like it could lead to new mental health treatments.
The team noted that more research is needed to understand why some people respond to ketamine and others do not, and to understand the neuropsychological risks of long-term repeated ketamine treatments – which are currently unknown.
Mann said that it would be a major benefit if ketamine could be used to lessen suicidal risk, and that designing rapid-acting antidepressants like ketamine without hallucinatory side effects or out-of-body experiences, that could be taken in pill form at home instead of in a clinical setting, is also important.
