Major depression is one of the most common mental illnesses in the United States, affecting over eight percent of adults– or twenty-one million– each year.
Despite depression being a highly treatable mental illness via medication, therapy, and lifestyle changes, though, about one-third of people diagnosed have what is known as treatment-resistant depression (TRD).
With TRD, medication may only partly relieve negative symptoms or result in no relief at all. So, scientists around the globe have been researching alternative therapies– one of which is ketamine.
Ketamine was first approved for antidepressant use by the Food and Drug Administration (FDA) in 2019. Later, the drug was also approved for treating suicidal ideation and behavior in adults.
And since then, ketamine has been shown to greatly impact TRD symptoms. Plus, unlike traditional antidepressants, which require about three weeks to become effective, ketamine is fast-acting– and its effects can be felt in as little as a few hours.
Despite the major triumph in treating TRD, though, the exact mechanisms associated with ketamine’s rapid antidepressant effect have remained unknown– until now.
The Paris Brain Institute recently conducted a clinical study consisting of twenty-six patients with TRD and thirty healthy control patients.
First, each group estimated the probability of forty generally “negative” events that could occur in their lifetimes– for example, getting into a car accident or falling ill.
Then, the researchers informed both TDR patients and healthy control subjects of the actual risk figure among the general population. And after receiving this information, both groups were asked to estimate their personal probability again.