For the last 50 years, medical professionals have used ketamine as an anesthetic, pain reliever and sedative in surgical settings. In recent years it’s been used recreationally as a party drug, otherwise known as Special K, and has also been approved for clinical use to address treatment-resistant depression. At large doses, some users report a deeply profound psychedelic trip. But what about a single ketamine infusion? Of course, ketamine is not a miracle cure, but can there be long-lasting effects from a solo treatment in a clinical setting? Some patients report a shift in their behavior and thought patterns that they attribute to this single dose. However, many clinics offer the standard ketamine treatment in a series of infusions. The research reveals the potential for a shorter path to healing.
What Is a Single Ketamine Infusion?
Ketamine is typically used in one of three ways: intranasally, intravenously or via intramuscular injection. When used in a clinical setting, intravenous ketamine infusions are preferred as they are the most bioavailable. According to Estelle Autissier, a registered nurse at Principium Psychiatry, intravenous (IV) administration is the best way for the brain to receive ketamine. The reason for this is because the bioavailability of IV ketamine is 100%. This means that the body and brain can use 100% of the ketamine that is given. However, the bioavailability from the intramuscular injection is only 93%, intranasal is 25–50%, and oral is 16–24%.
The Mental Health Center at Cedars-Sinai Medical Center reports: “Over 10 studies have shown that ‘a single ketamine infusion rapidly reduced the severity of suicidal thinking, within 24 hours in more than half the patients, and with benefits observed up to 1 week.'” This is powerful data suggesting that ketamine has the ability to reduce suicidal and self-harming behaviors, much like lithium or clozapine.
“Recent data suggest that Ketamine, given intravenously, might be the most important breakthrough in antidepressant treatment in decades.”
Thomas Insel, MD, Director of the National Institute of Mental Health, 2002–2015
The entire appointment for a single ketamine infusion is roughly 60–90 minutes. However, the time may vary depending on the treatment center and various factors pertaining to the patient’s health and recommended treatment plan. Can this single-dose affect the brain significantly enough—and what is the correct dosage to know for sure?
Default Mode Network
The idea of the default mode network (DMN) is a relatively new concept. Researchers noticed unexpected brain activity in patients who were supposed to be in a resting state, typically with their eyes closed, not performing any kind of mental task. The DMN appears to be active when “individuals are focused on their internal mental-state processes, such as self-referential processing, interoception, autobiographical memory retrieval, or imagining future.”
People with severe depression and even chronic pain symptoms have higher levels of DMN activity. A symptom of depression is circular or ruminative thinking, continually dwelling on painful memories or events. DMN is particularly active while the mind is cycling in this pattern. Therefore, when you reduce DMN activity, ruminative thinking also subsides.
And what does ketamine do? It reduces the activity levels of the DMN.
Single Ketamine Infusion Dosage
When administered by a nurse or doctor to treat depression in a clinical environment, a standard dose of ketamine is 0.5 mg/kg. Patients respond to doses as small as 0.1 mg/kg on the low end, with others requiring up to 0.75 mg/kg. The infusion is administered over the course of 40 minutes. However, in some settings, the window for administration could be anywhere from 2–100 minutes. The dosage found most effective during clinical trials was 0.5 mg/kg over 40 minutes. Therefore, this is the most common standard in a clinical setting.
Ketamine Infusion Therapy
Many ketamine treatment centers approach ketamine therapy in combination with other types of psychotherapy for a well-rounded approach to wellness. However, some clinics offer only stand-alone treatment. Before beginning ketamine treatment, patients should talk with a doctor to develop a plan to best treat their specific condition. It’s helpful to know what a standard course of treatment looks like, and what conditions ketamine is known to treat or help with like eating disorders, depression, or addiction.
How Many Ketamine Sessions Should You Have?
The number of sessions recommended may vary based on the reason for treatment. A typical protocol for treatment-resistant depression is six ketamine infusions within a 12-day window. This schedule of regularity is shown to help reduce symptoms of depression and maintain positive effects. Additionally, booster infusions may be recommended to sustain results.
Research shows that ketamine for depression has a 70% response rate in a series of six treatments. However, since ketamine is so quick-acting, patients may feel the effects of a single ketamine infusion within 24 hours after the initial treatment. The 30% of patients who do find their desired result from ketamine treatment will know whether to continue with the entire protocol within the first few treatments, instead of taking conventional oral antidepressants, which take roughly six to eight weeks to determine whether or not they are effective.
Therapeutic Developments
While most antidepressants target a “monoamine” neurotransmitter such as dopamine, norepinephrine or serotonin, ketamine acts on the glutamate receptors. Glutamate is the brain’s most common and abundant excitatory neurotransmitter in the nervous system. It is responsible for regulating the brain’s ability to process emotions and cognitive thoughts.
Glutamate produces and regulates Gamma Aminobutyric Acid (GABA), an inhibitory neurotransmitter whose primary role is to reduce excitability and promote calmness in the nervous system. If a person has high levels of glutamate and low GABA, he or she might experience anxiety. Alternatively, low levels of glutamate and increased GABA can lead to depression.
Ketamine therapy is most often associated with treatment-resistant depression, but it’s not the only case in which this therapy is used.
- Alcohol Use Disorder (AUD) — A 2020 study on single ketamine infusion for AUD showed that patients were more prone to abstinence and had a delayed time to relapse. The patients showed no side effects and tolerated the infusions well.
- Bipolar Depression — A single ketamine infusion was given to 18 bipolar depressed patients who regularly took mood-stabilizing drugs. Within three days, the patients were showing improved neuropsychological performance without the effects of antidepressants.
- Social Anxiety Disorder (SAD) — Many patients with SAD struggle to find adequate relief of symptoms. Ketamine is shown to be an effective treatment for many similar psychiatric disorders (depression, bipolar depression, and possibly obsessive-compulsive disorder). It therefore is believed to be a potential treatment for SAD. Initial research (see paragraph 4 of this linked NIH study) demonstrates a reduction in anxiety in patients who also experience major depressive disorder.
Choosing the Right Treatment
Does everyone benefit from ketamine therapy? No, certainly not. But it is a viable option for those who have exhausted other options and wish to try a longer-lasting treatment with minimal side effects. While early evidence suggests that there are benefits to a single ketamine infusion, it’s not a wonder drug or a cure-all. For anyone wishing to pursue ketamine treatment, be sure to thoroughly research all clinics, speak with a doctor, and establish a personalized protocol before the initial course of treatment.
Questions to ask a ketamine clinic include:
- Where did your clinicians/doctors train in ketamine therapy?
- What is your success rate for treatment?
- Do you have all the necessary safety equipment in case of an emergency?
- Is the treatment area comfortable and private?
- Are guests allowed during treatment?
- Does my insurance cover infusions?
- What is the difference between ketamine vs. esketamine?
Having a list of questions ready can help provide a sense of preparedness before deciding to begin treatment. If you have experience with ketamine therapy, drop a comment below and let us know how you liked your experience, and if you opted for a single treatment or a series.
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Disclaimer: Ketamine is potentially categorized as an illegal drug. Reality Sandwich is not encouraging the use of this drug where prohibited. However, we believe that providing information is imperative for the safety of those who choose to explore this substance. This guide is intended to give educational content and should in no way be viewed as medical recommendations.
