Ketamine has been used safely as an anesthetic for more than 60 years — but its antidepressant properties were largely unknown until the early 2000s, when researchers discovered it could produce dramatic, rapid relief in patients who had failed multiple medications. That discovery set off a wave of scientific investigation into how and why it works, and what the answers revealed changed the way researchers think about depression itself. At InfuseRVA in South Chesterfield, we believe patients deserve to understand the science behind any treatment they are considering — not just the outcomes, but the mechanism.
How Antidepressants Have Worked Until Now
For decades, the dominant theory of depression centered on monoamine neurotransmitters — primarily serotonin and norepinephrine. The medications developed around this theory, including selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs), work by increasing the availability of these neurotransmitters in the synaptic space between neurons. This approach has helped many people significantly.
But roughly one-third of people with major depressive disorder do not respond adequately to two or more of these medications — a pattern clinicians call treatment-resistant depression (TRD). For this population, the monoamine model alone does not explain what is driving their symptoms, and monoamine-targeting treatments alone are unlikely to resolve them. The question researchers began asking was: what else is happening in the depressed brain, and what else might we target?
The Glutamate System: A Different Mechanism
The answer, in significant part, turned out to involve glutamate — the brain’s primary excitatory neurotransmitter. Research over the past two decades has shifted attention toward glutamate signaling as a central factor in treatment-resistant depression, particularly in how it relates to synaptic plasticity: the brain’s ability to strengthen, weaken, form, and reorganize connections between neurons.
Ketamine infusion therapy works by blocking a specific type of glutamate receptor called the N-methyl-D-aspartate receptor, or NMDA receptor. This is a fundamentally different target than anything SSRIs act on. When ketamine blocks NMDA receptors on a class of inhibitory neurons called GABAergic interneurons, those neurons become less active. Their normal function is to suppress the firing of adjacent excitatory neurons — the pyramidal cells that form the backbone of cortical processing. When that suppression is lifted, the result is a rapid surge of glutamate release in key brain regions, particularly the prefrontal cortex and hippocampus (Antos et al., 2024).
The BDNF Cascade: Where Neuroplasticity Begins
That glutamate surge is not the endpoint — it is the beginning of a molecular cascade with significant implications for brain structure and function. The released glutamate activates a different class of receptors called AMPA receptors, and this activation sets off a series of downstream events that ultimately result in the production of brain-derived neurotrophic factor, or BDNF (Krystal et al., 2024).
BDNF is a protein often described as a growth factor for neurons. It supports the survival of existing nerve cells, promotes the growth of new dendritic spines — the tiny protrusions through which neurons communicate — and strengthens the synaptic connections between them. In the brains of people with depression, BDNF levels in the prefrontal cortex and hippocampus are often reduced, and this reduction is associated with the shrinkage of neural architecture that has been observed in imaging studies of depressed patients (Kang et al., 2022).
Ketamine’s NMDA blockade also interrupts a protein called eEF2 kinase, which normally suppresses BDNF production. When eEF2 kinase is inhibited, BDNF translation is de-suppressed — meaning the brain effectively turns back on a process that depression may have turned down (Krystal et al., 2024). The result is a rapid increase in BDNF that activates the mTOR signaling pathway, which in turn stimulates synaptogenesis: the formation of new synaptic connections. This is what researchers mean when they describe ketamine as promoting neuroplasticity.
Why Speed Matters
One of the most clinically significant features of ketamine’s mechanism is how quickly these effects occur. Traditional antidepressants require weeks of consistent use to produce therapeutic benefits, in part because the changes they drive — gradual modulation of serotonin availability and receptor sensitivity — accumulate slowly. Ketamine’s downstream cascade, by contrast, can produce measurable antidepressant effects within hours of a single infusion (Antos et al., 2024). In a series of six infusions administered over approximately two to three weeks, as we typically administer here at InfuseRVA, patients may begin to notice changes early in the treatment course.
This rapid onset matters enormously for patients who are suffering acutely — particularly those with severe depression treatment in South Chesterfield, PTSD, or chronic pain conditions that have not responded to other approaches. It also matters because the neuroplasticity window opened by ketamine may make concurrent psychotherapy more effective, which is one reason we encourage patients to maintain or begin a therapeutic relationship alongside treatment.
What the Treatment Looks Like in Practice
Understanding the science helps clarify what you are actually receiving during a ketamine infusion. At InfuseRVA, IV ketamine is administered at sub-anesthetic doses — meaning amounts far below what would be used for surgical anesthesia — in a carefully controlled clinical environment. Our medical team evaluates every patient before treatment begins, reviewing your medical history, current medications, and specific symptoms to determine whether ketamine therapy may be appropriate for your situation.
A standard course for mood disorders involves six infusions. You will need a confirmed driver for each session, and we ask that you avoid food for four hours and liquids for two hours beforehand. Activity restrictions apply for 24 hours after each infusion, including no driving, strenuous physical activity, or operation of machinery. These protocols exist to protect you, and our team walks you through every expectation before your first appointment. For answers to common questions about what the process involves, our ketamine infusions FAQ page is a helpful starting point.
We want to address a concern we hear often: many patients worry that ketamine is the same as the illicit drug they have heard about. At therapeutic doses, administered intravenously in a supervised medical setting, ketamine’s effects and risks are categorically different from recreational use. The dose, route of administration, clinical monitoring, and therapeutic context are all distinct. Screening is required precisely because ketamine is not appropriate for everyone — and that is a feature of responsible care, not a barrier.
An Honest Word About Cost
IV ketamine infusion therapy is not covered by most insurance plans. We are transparent about this at every consultation because we believe you deserve to make a fully informed financial decision. Our team will walk you through out-of-pocket costs before you commit to anything, and we accept cash and major credit cards. We serve patients across the South Chesterfield and greater Richmond area — including Chester, Mechanicsville, and Powhatan — and our Monday through Friday hours are designed to accommodate patients who are working around a standard schedule. Results vary by individual, and our goal is to give you accurate expectations from the start, not promises.
Frequently Asked Questions
How does ketamine work differently from antidepressants? Standard antidepressants target the serotonin and norepinephrine systems. Ketamine targets the glutamate system — specifically NMDA receptors — and produces its effects through a different molecular cascade involving BDNF production and synaptogenesis. This is why ketamine may help patients who have not responded to multiple antidepressants: it is working on a different part of the biology.
How long do the effects of ketamine last? This varies by individual and condition. Some patients maintain relief for weeks to months after a standard six-infusion series. Others benefit from periodic maintenance infusions. There is no single answer that applies to all patients, which is why we monitor your response throughout the treatment series and discuss next steps based on what we observe.
Is ketamine safe for long-term use? Ketamine has been used in medical settings for over 60 years, and the safety profile at sub-anesthetic doses administered in clinical settings is well-studied. That said, long-term protocols for ketamine as an antidepressant are still being refined, and we discuss the current evidence honestly at your consultation. Every treatment decision is made with your full medical history in view.
Does ketamine work for conditions other than depression? At InfuseRVA, we offer ketamine infusion therapy for a range of conditions including treatment-resistant depression, anxiety, PTSD, OCD, bipolar disorder, chronic pain, and suicidal ideation. The evidence base varies by condition, and we will explain what the research currently supports for your specific situation during your evaluation.
What disqualifies someone from ketamine therapy? Certain psychiatric and medical histories may make ketamine therapy inadvisable, including active psychosis, uncontrolled hypertension, or substance use disorders. This is why a thorough pre-treatment evaluation is required. Our medical team will identify any contraindications and discuss alternative options if ketamine is not appropriate for you.
Key Takeaways
- Ketamine works through the glutamate system — specifically by blocking NMDA receptors — rather than the serotonin and norepinephrine pathways targeted by standard antidepressants, which is why it may help patients who have not responded to those medications.
- NMDA receptor blockade triggers a cascade involving BDNF production, mTOR activation, and synaptogenesis — the formation of new neural connections — which is the biological basis for ketamine’s neuroplasticity effects.
- Ketamine can produce antidepressant effects within hours of a single infusion, in contrast to the weeks required by traditional medications, making it particularly relevant for patients in acute distress.
- At InfuseRVA, IV ketamine is administered at sub-anesthetic doses in a supervised clinical environment following a thorough pre-treatment evaluation; results vary by individual.
- IV ketamine therapy is not covered by most insurance plans; our team discusses costs transparently at every consultation before any commitment is made.
The science behind ketamine is still being refined — researchers continue to investigate its full range of mechanisms — but what is already established represents a meaningful shift in how treatment-resistant mental health conditions can be addressed. If you have questions about whether ketamine therapy may be appropriate for your situation, call us at804-895-4636 or schedule a consultation at our South Chesterfield clinic. Our medical team will give you a clear, honest picture of what the treatment involves and what you might reasonably expect.
References
Antos, Z., Żukow, X., Bursztynowicz, L., & Jakubów, P. (2024). Beyond NMDA receptors: A narrative review of ketamine’s rapid and multifaceted mechanisms in depression treatment. International Journal of Molecular Sciences, 25(24), 13658. https://pmc.ncbi.nlm.nih.gov/articles/PMC11728282/
Kang, M. J. Y., Hawken, E., & Vazquez, G. H. (2022). The mechanisms behind rapid antidepressant effects of ketamine: A systematic review with a focus on molecular neuroplasticity. Frontiers in Psychiatry, 13, 860882. https://pmc.ncbi.nlm.nih.gov/articles/PMC9082546/
Krystal, J. H., Kavalali, E. T., & Monteggia, L. M. (2024). Ketamine and rapid antidepressant action: New treatments and novel synaptic signaling mechanisms. Neuropsychopharmacology, 49, 41–50. https://www.nature.com/articles/s41386-023-01629-w
Medical Disclaimer
The information in this blog is for educational purposes only and does not constitute medical advice. Ketamine infusion therapy should only be pursued under the supervision of a licensed medical provider following a thorough evaluation of your full medical and psychiatric history. Individual results vary. If you are experiencing a mental health crisis or thoughts of self-harm, please call or text 988 to reach the Suicide and Crisis Lifeline or go to your nearest emergency room.
