Ketamine infusions
A rapid-acting antidepressant treatment for treatment-resistant depression and severe anxiety disorders, in Lausanne, Switzerland.
What is ketamine?
Ketamine is an N-Methyl-D-aspartate (NMDA) receptor antagonist which has been in use since the 1960s as an anaesthetic for children and adults. It therefore has a long track record for safety. During treatment, the medication is administered intravenously (oral, sublingual and intramuscular routes are still under investigation).
When used in much lower doses than for anaesthesia, ketamine has a powerful antidepressant effect which has only recently been identified and is currently being extensively investigated.
The precise mechanism of the antidepressant action is still being unravelled since the NMDA antagonism does not seem to fully explain the effect observed. Ketamine also appears to increase the levels of dopamine, noradrenaline and serotonin in the brain. It is associated with various biochemical pathways involved in synaptic plasticity. It induces rapid modifications in the presynaptic mechanism of the hippocampus similar to those observed with long-term administration of a conventional antidepressant.
Ketamine’s antidepressant action appears within a few hours compared to the several weeks needed for traditionally used medication against depression.
The treatment should not however be considered as a “cure” for depression but as an adjunct that enables other biological or psychological treatments to work.
Ketamine is also indicated for some conditions of chronic pain and is extremely effective.
Who are ketamine infusions indicated for?
Intravenous ketamine infusions are indicated for patients with severe major depression (unipolar or bipolar) without psychotic symptoms and for various conditions of chronic pain.
Other indications include treatment-resistant anxiety disorders such as generalised anxiety disorder, as well as obsessive-compulsive disorder (OCD) and post-traumatic stress disorder (PTSD).
It is contraindicated in the case of schizophrenia, psychosis or epilepsy.
Ketamine also has a marked anti-suicidal effect, even after a single dose.
Non-pharmacological alternative
For the most severe forms of treatment-resistant depression, particularly when an immediate response is needed, electroconvulsive therapy (ECT) may be considered as a first-line interventional treatment.
Is ketamine effective?
Antidepressants are effective in around 50% of patients with depression, and this probability falls markedly after each previous treatment failure. In the case of treatment-resistant depression, the observed response rates with ketamine are especially high, in the range of 50 to 70%, and 30% of patients achieve a full remission.
Some patients respond strongly from the very first infusion; others require more sessions.
Although ketamine acts more rapidly than other types of antidepressant treatments, the risk of relapse after a single infusion is high. This is why infusions need to be repeated.
A few patients will start to feel a difference immediately after the first infusion, however fluctuations of mood, sadness or depression are possible between infusions. A total of 10 infusions will be recommended over a period of 10 weeks, at decreasing frequency in order to bolster the antidepressant effect and avoid sudden relapses.
Subsequently, “booster” infusions can be administered at variable frequency, depending on the evolution of the condition. On average, these booster infusions are administered every four weeks. If no positive response is observed after five infusions, the protocol is interrupted and other therapies may be suggested.
Booster infusions
Patients who have previously completed a course of ketamine infusions — whether at LCIP or another clinic — may benefit from periodic booster sessions to sustain the antidepressant effect. Boosters are typically administered as single infusions or short series of 2–3 sessions, depending on clinical response. An abbreviated psychiatric assessment is required prior to the first booster session to review current symptoms and medication. This option is particularly suited to patients travelling to Switzerland who wish to combine a brief treatment course with their stay.
Ketadex: combining ketamine with dexmedetomidine
For some patients, the combination of ketamine with dexmedetomidine (Ketadex) can enhance and prolong the therapeutic benefits while making the experience more comfortable. Dexmedetomidine reduces the intensity of dissociative effects sometimes caused by ketamine alone, and adds its own antidepressant and anxiolytic properties, potentiating the overall response. This combination is particularly suited for patients who are apprehensive about or do not tolerate the dissociative effects of ketamine.
Why no ketamine-assisted psychotherapy?
Our intravenous ketamine practice is based on scientifically validated pharmacological protocols. Dissociative effects, which some consider a “support for psychological exploration,” are for us a potential pharmacological marker of efficacy, managed under rigorous anaesthetic monitoring.
We therefore do not offer ketamine-assisted psychotherapy (KAP).
This position is supported by a growing body of scientific evidence. A prospective study of over 600 patients (Moore et al., 2025) demonstrates that adding psychotherapy during treatment provides no additional benefit compared to ketamine alone, for both depression and PTSD. Two recent systematic reviews (Veraart et al., 2026; Simpson & Juruena, 2026) confirm that controlled trials comparing KAP with ketamine alone find no significant difference between the two approaches.
Efficacy depends on optimal dosing, adjusted according to each patient’s clinical response. Studies show that personalised doses are significantly more effective than standardised protocols. At LCIP, each infusion is individualised with continuous anaesthetic monitoring and regular psychiatric follow-up.
How is the treatment given?
All prospective patients have to undergo a medical examination with both a psychiatrist and an anaesthetist to determine if the treatment can be done. Patients with severe cardiovascular or respiratory problems may need further tests before the first infusion or a modification of the treatment.
Safety is paramount at the Centre for Interventional Psychiatry: no treatment is undertaken if the medical team has any doubt or if the risk of complications is judged unreasonable.
The treatment is performed at the Centre for Interventional Psychiatry by a team of highly qualified and experienced anaesthetists. A nurse anaesthetist or an anaesthetist is present throughout the procedure. A psychiatrist is also constantly available.
The patient is settled in a comfortable, dimly lit room and can listen to soft music. External stimuli have to be reduced to a minimum during the time the infusion is done. Once the infusion starts, vital parameters such as blood pressure, oxygen saturation and the electrocardiogram are constantly monitored.
Each infusion lasts approximately 45 minutes and continues to be monitored for at least 30 minutes afterwards. Most patients describe the experience as “surprising”. Immediately after the infusion, some patients will experience great well-being while others may feel slightly confused for a short time. Expert medical care is constantly available and will intervene should it be necessary.
All ketamine infusions are supervised by Dr Mall, in collaboration with our anaesthesiology team.
Important instructions
Before each infusion, it is imperative that the patient has an empty stomach from six hours before for solid food and two hours for liquids. Consumption of alcohol or other illegal substances is obviously not permissible.
After each infusion, the patient must be accompanied back home and must not drive for 24 hours.
Side effects and risks
Side effects
The most common side effects are dizziness, blurred vision, hypertension, tachycardia or nausea. Dissociative effects are frequently observed such as perturbation of functions that are normally integrated — consciousness, memory, identity or perception of the surroundings (for example, a feeling of detachment from one’s body), sleepiness or sometimes hallucinations.
Most patients will experience moderate dissociative effects. This is an intended effect of the centre’s protocol and a possible marker of treatment efficacy.
All these reactions can happen during the infusion. They are monitored and controlled as necessary by specific medication. Side effects disappear quickly on their own when the procedure ends. The doses used in depression treatment are significantly lower than those used for anaesthesia in surgery, for example.
Interactions with other drugs
There is no need to stop an ongoing antidepressant. Ketamine can be given alongside all classes of antidepressants, including lithium. Ketamine provides rapid improvement while waiting for the effect of standard medication to set in.
However, there may be reduced benefits with some benzodiazepines (Temesta, Xanax, Lexotanil, etc.) or some antiepileptic drugs (lamotrigine).
Ketamine addiction risk
Although ketamine can be misused recreationally, it does not meet the criteria for physical dependence. Tolerance may, however, develop with prolonged use.
Is ketamine covered by insurance?
Not reimbursed
Ketamine infusions are not reimbursed by either basic or complementary insurance schemes in Switzerland. The patient has to meet the entire cost of treatment as well as of the monitoring by specialists in psychiatry and anaesthesia.
More information on costs and payment terms is available upon request.
