What is ketamine infusion therapy?

Among the details released Thursday about the death of actor Matthew Perry was that the “Friends” star had undergone ketamine infusion therapy.

The coroner concluded that the treatment – which is available in both the US and the UK – was not responsible Ketamine, which prosecutors say was administered to him illegally, is responsible for Perry's death.

Five people, including two doctors, Perry's assistant and a suspected drug dealer were charged for providing the medicine outside of his treatment plan.

Perry, 54, had spoken openly about his drug past, and prosecutors believe the defendant profited from his addiction.

Ketamine is an anesthetic that can be used in medical settings to treat depression, anxiety and pain.

However, it also has dissociative effects – that is, it can distort the perception of sight, sound and time, and also has calming and relaxing effects. Therefore, it is also used illegally.

According to addiction counseling service Talk to Frank, ketamine can increase a person's heart rate and blood pressure and cause confusion and agitation in users, which can lead to them unknowingly harming themselves.

Chronic ketamine use is associated with liver damage and causes bladder problems such as incontinence.

Ketamine is used to treat depression in cases where conventional antidepressants have not been effective.

“On a biological level, it probably shuts down the area of ​​the brain responsible for disappointment,” says Prof Rupert McShane, a psychiatrist at the University of Oxford who runs an NHS ketamine treatment clinic. “This area is probably involved in depression.”

Dr Rajalingam Yadhu, a consultant at the Royal Free Hospital in London who also runs Save Minds, a ketamine infusion therapy clinic, told the BBC that the patients he treats suffer from chronic depression and have typically tried at least seven different medications without improvement.

“These are people who have tried everything in life, [are] extremely suicidal – and would kill themselves if they had the chance.”

Famous people have also used this treatment. In addition to Perry, billionaire entrepreneur Elon Musk has also stated that he received ketamine to treat depression.

In an interview with CNN in March, the X and Tesla owner said the drug was “helpful to get out of the negative state of mind.”

In ketamine infusion therapy, the drug is administered intravenously in smaller doses than those used for anesthesia.

“For depression, you use a lower dose than for chronic pain, a much lower dose than what patients receive as an anesthetic,” says Dr. Mario Juruena, a psychiatrist at King's College London who specializes in treatment-resistant mental disorders.

Ketamine works faster than conventional antidepressants – but its effects also wear off more quickly.

“It has a short half-life, so the duration of effects in patients is sometimes quite short,” Dr Juruena told the BBC, stressing the importance of monitoring patients' mental state for relapses into depression.

Dr. Yadhu says that unlike other common antidepressants, ketamine affects nerves that interact with the chemical glutamate, the most abundant neurotransmitter in the nervous system.

Some studies suggest that ketamine may also help reverse synaptic pruning – the removal of neurons – which, while naturally occurring, can also be linked to chronic stress and depression.

“When you get depressed, the connections in the brain seem to shrink,” Prof McShane told the BBC. “It's almost as if when you're depressed, some of the neurons are like a tree in the winter – and then the ketamine makes them more like a tree in the spring.”

He adds that the drug likely reduces suicidal thoughts and the “cycle of rumination” that feeds depression.

Experts are researching why it might help some patients but not others.

Dr Juruena told the BBC that over 60 percent of patients responded well to ketamine treatment – but added that this was usually alongside taking other antidepressants or psychotherapy.

Doctors caution that negative side effects can occur when taking ketamine, even under medical supervision, but Dr. Juruena says this is less common due to the lower dosage.

Dr. Yadhu says many of his patients have had positive experiences, but some have been unpleasant and can bring back bad memories.

Prof. McShane notes: “While ketamine can be very effective in people who have not responded to anything else, one problem is that you have to keep taking it – and we are just not used to that being a good idea.”

Dr. Yadhu says he does not treat people with addictive tendencies with ketamine – although some doctors are investigating it as a treatment for drug and alcohol addiction.

However, administering ketamine via an “infusion” is not the only way to treat people with ketamine.

Dr. Juruena says it can also be given as an injection, nasal spray or capsule.

According to experts, the dose of ketamine used in an infusion treatment must be precise and low to achieve an antidepressant effect.

However, an autopsy revealed that Perry's blood contained high levels of ketamine and that he had died from the “acute effects” of the drug.

The coroner also noted that his last ketamine infusion therapy session had taken place more than a week before his death – by which time the effects of the drug may have already worn off.

They also said the concentration of ketamine in Perry's body was much higher at the time of his death.

Prosecutors alleged that Perry's assistant administered at least 27 doses of ketamine in the four days before his death.