What is Ketamine Therapy?
Ketamine has been used for decades as an anesthetic in medical settings. At much lower doses than used in surgery, it has rapid antidepressant and anti-suicidal effects for some people, especially those who have not responded to traditional treatments.
There are three main ways ketamine is used in mental health:
IV or IM ketamine in clinics (infusions or injections)
Intranasal esketamine (Spravato), which is FDA-approved for treatment-resistant depression and is given in certified clinics
Off-label ketamine (including some at-home models), which may involve lozenges or other routes, typically combined with therapy
How ketamine works (in simple terms)
Ketamine affects glutamate, an important brain chemical involved in learning and plasticity. It appears to:
Increase synaptic connections (how brain cells communicate)
“Loosen” rigid patterns of thinking and emotional reactions
Create a window where the brain is more flexible and open to change
Because of this, many providers pair ketamine with therapy so that clients can use that window to process trauma, shift beliefs, and build new emotional patterns.
What conditions ketamine is used for
Research and clinical practice use ketamine for:
Treatment-resistant depression
Suicidal thoughts
PTSD
Some anxiety disorders and chronic pain conditions
Only intranasal esketamine (Spravato) has formal FDA approval for treatment-resistant depression and depressive symptoms in adults with major depressive disorder with acute suicidal ideation or behavior. Other uses are “off-label,” which means they rely on emerging research and clinical experience rather than full FDA indications.
What a typical course can look like
Protocols vary depending on the form:
Esketamine (Spravato) in clinic
Often twice a week for the first 4 weeks
Then weekly or every other week
Each visit includes monitoring in the clinic for about 2 hours because of possible blood pressure changes or dissociation
IV or IM ketamine
Often 6 to 8 infusions over 2–4 weeks for the “acute” phase
Some people then space out “booster” sessions over time
Side effects and safety
Common short-term effects during or after a dose:
Dissociation (feeling disconnected from body or environment)
Changes in perception, such as visual distortions
Nausea, dizziness, increased blood pressure, or heart rate
Fatigue or mild confusion afterward
Less common but important risks:
Worsening mood or anxiety for some people
Substance use risk, especially outside structured medical care
Bladder problems with long-term, high-frequency recreational use (less clear with medically supervised, lower doses but still monitored)
Because of these risks, ketamine should always be used under medical supervision with a clear treatment plan, informed consent, and monitoring of mental and physical health.