ADHD News & Research

Study: Ketamine Infusions Reduce Depression, Anxiety, Suicidal Ideation in Some Patients

After a series of ketamine infusions, half of patients with treatment-resistant depression reported a reduction in symptoms, according to a new study of 424 patients.

October 14, 2022

Intravenous ketamine infusions could effectively reduce symptoms in patients with treatment-resistant depression (TRD), suicidal ideation (SI), and anxiety, according to a new study published in the Journal of Clinical Psychiatry. The study analyzed data from 424 TRD patients who received ketamine injections from November 2017 to May 2021. 1

Patients received six ketamine infusions at a starting dose of 0.5 mg/kg, each one lasting around 40 minutes. Half of the patients responded to treatment within six weeks, and 20% reported remission of their depression symptoms. (After 10 infusions, response and remission rates for depression were 72% and 38%, respectively.) During the same period, 50% of patients with self-harm/suicidal ideation reported entering remission or had fewer symptoms. One-third of patients reported decreased anxiety symptoms.

“The high rates of response and remission were similar to those for interventional treatments in community samples of TRD,” researchers wrote. However, they acknowledged several limitations of the study, which included no control group and used self-reported patient data. “Comparative efficacy trials with other interventions and randomized controlled trials of racemic ketamine infusion as the primary treatment for SI are needed,” researchers said.

Roberto Olivardia, Ph.D., clinical psychologist and clinical instructor of psychology at Harvard Medical School, discussed ketamine treatment for depression in the 2019 ADDitude webinar titled “The ADHD-Depression Connection in Adults: Understanding the Link, Distinct Symptoms, and First-Line Treatments.”

“Ketamine is a hallucinogenic drug with properties that can be very useful in treating depression,” Olivardia said. “The drug affects glutamate and GABA — excitatory and inhibitory neurotransmitters of the brain. Ketamine promotes synaptic connections within the brain for learning and memory, but it can also block other receptors, leading to rapid antidepressant action. Studies have shown that the drug reduces or eliminates very acute or distressing symptoms of depression, including suicidal thoughts. Other studies show that 60% or more of patients find relief from depressive symptoms with these infusions.

“The drug, still considered experimental, is used for severe cases of treatment-resistant depression,” he continued. “When other antidepressant medications have failed, or if there’s acute suicidality, ketamine infusions may be appropriate.”

The U.S. Food and Drug Administration has not approved ketamine to treat psychiatric disorders. However, the “S” form of ketamine, which is derived from ketamine and known as Spravato (esketamine), is a Schedule III controlled substance that was approved by FDA in 2019 as a nasal spray for treatment-resistant depression in adults and depressive symptoms in adults with major depressive disorder with acute suicidal ideation or behavior, in conjunction with an oral antidepressant.2

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1 Oliver, P. A., Snyder, A. D., Feinn, R., Malov, S., McDiarmid, G., & Arias, A. J. (2022). Clinical Effectiveness of Intravenous Racemic Ketamine Infusions in a Large Community Sample of Patients with Treatment-Resistant Depression, Suicidal Ideation, and Generalized Anxiety Symptoms: A Retrospective Chart Review. The Journal of Clinical Psychiatry. 83(6), 21m14336.

2U.S. Food and Drug Administration. (February 2022). FDA Alerts Health Care Professionals of Potential Risks Associated with Compounded Ketamine Nasal Spray.