The results, recently published in the Journal of Affective Disorders, suggest that an at-home approach using ketamine tablets that dissolve under the tongue rather than intravenous (IV) infusion or intramuscular injection could make ketamine therapy more accessible.
Several sessions of at-home ketamine therapy supported by telehealth are a safe and effective way to treat moderate to severe anxiety and depression, a new study found. But experts caution that more rigorous studies are still needed to determine how well ketamine therapy compares to traditional treatments for anxiety and depression.
Ketamine, once mainly used as an anesthetic, is gaining ground as a potential treatment for depressive disorders and suicidal ideation in clinical settings. Medical professionals may administer ketamine directly into a vein (intravenous or IV) or into a muscle (intramuscular injection) in clinical settings.
The Food and Drug Administration (FDA) has also recently approved esketamine, a form of ketamine that’s administered with a nasal spray. Esketamine therapy may be used in conjunction with an oral antidepressant for the treatment of depression in people who didn’t benefit from antidepressants alone.
In addition, ketamine tablets may also be dissolved under the tongue (sublingual), which has been shown to improve symptoms in people with treatment-resistant depression. Sublingual ketamine therapy was used in the new study.
In the current study, which was the largest clinical study of its kind to date, over 1,200 adults received at-home sublingual ketamine therapy through Mindbloom, a telehealth platform that offers this therapy in 30 U.S. states.
All participants included in the study were diagnosed with severe anxiety, moderate to severe depression, or both. Before their first medication session, participants met with a psychiatrist through a video call. The clinician evaluated people to see if ketamine therapy would be a good fit for them.
“Although at-home sublingual ketamine therapy can be an effective, safe treatment option for people experiencing anxiety or depression, it is not for everyone,” said study author Dr. Leonardo Vando, Mindbloom’s medical director. “That’s why Mindbloom’s clinicians play a critical role in determining whether treatment is appropriate for each prospective client.”
Throughout the study, participants met with a behavioral coach who helped participants prepare for their first session and provided support between sessions, including by text message.
The at-home therapy protocol included four weekly medication sessions. During each session, participants dissolved the ketamine tablet under their tongue, put on an eye mask, and listened to music for an hour. Afterward, they wrote in a journal about the experience, which helped them reflect on and integrate their feelings and insights. As a precaution, study participants were also given a digital blood pressure cuff so they could monitor their blood pressure after taking the medication since ketamine can increase blood pressure.
After four medication sessions, almost 89% of people saw improvements in their anxiety or depression symptoms, either immediately or after the first two sessions. Overall, almost 63% of people had a 50% or greater reduction in their anxiety or depression symptoms. In addition, researchers saw a decrease in the number of participants who reported having suicidal thoughts or ideas.
Side effects of the ketamine treatment were rare, reported by fewer than 5% of participants. Only four people dropped out of the treatment due to adverse events.
“This study demonstrated that at-home treatments can be incredibly effective with a low rate of side effects, especially when compared against studies for SSRIs [selective serotonin reuptake inhibitors],” Vando said. (SSRIs are commonly prescribed antidepressants and include Celexa, Prozac, and Zoloft.)
Subhdeep Virk, MBBS, clinical associate professor of psychiatry and behavioral health at The Ohio State University Wexner Medical Center in Columbus, who was not involved in the new study, said one of the strengths of the research was a large number of participants. Still, she noted the study is just a “starting point” and called for more research, in particular a randomized placebo-controlled clinical trial (RCT).
This type of study would allow researchers to compare the safety and effectiveness of at-home ketamine therapy to standard treatments for anxiety, depression, or both. In the new study, there was no control (or comparison) group.
Virk added that following patients longer — from 1 to 6 months after the end of treatment would also provide information on the long-term benefits of at-home ketamine therapy.
“We do have a lot of data on ketamine,” Virk said. “We already know that it helps much more quickly than some of the other antidepressants. What we don’t know about this treatment is how sustained those effects are.”
In her clinic, Virk said she provides both IV infusion and intranasal ketamine therapy to patients, so she’s familiar with its potential as a treatment for anxiety and depression. However, because this is a newer treatment, she tells patients she’s “cautiously optimistic” about ketamine’s role as a treatment.
“We see results if you compare ketamine to traditional antidepressants, the response is quicker,” Virk said. “But it is not a miracle treatment. It has its limitations, and we still need to be careful in selecting patients when we are providing these treatment options.”
Parvathy Sukumaran 
