Ihor Kholodilo should probably not have survived. The military psychologist and medic was evacuating comrades in early 2023 when his jeep was hit by a Russian tank shell. He was left barely able to communicate. Operations saved his heart and vision. But doctors were unable to correct his slur and stammer.

He tried all kinds of radical therapies, but nothing helped. Then he met Dr Vladislav Matrenitsky, a pioneer of psychedelic-assisted psychotherapy, who posed an unexpected question. Would he try ketamine?

Kholodilo did not expect much, but the results were astonishing. After one session his stammer all but disappeared. Another five and he was almost back to normal. Gone were the nightmares and the fears about daily life. Ketamine therapy was not easy, he says, but it allowed him to resolve the trauma that caused his symptoms: “I returned to what you could call life … I felt light, just blessed.”

Ketamine has been legal in Ukraine to treat mental illness since 2017. The therapeutic use of psychedelics has a long history, and was explored in America in the 1950s and ’60s. After the hippie movement it fell out of political favour, and for a while psychedelics were equated with narcotics like heroin. But in the past decade or so they have experienced a renaissance.

Now the war is putting Ukraine at the forefront of the treatment. Matrenitsky, who runs the country’s only clinic offering ketamine therapy, says he has handled nearly 300 patients suffering from depression, post-traumatic stress disorder or anxiety. A growing share are soldiers.

A 40-minute session at Matrenitsky’s clinic, on the top floor of a drab children’s hospital in north Kyiv, costs 4000 hryvnia ($162), although the clinic provides some soldiers with treatment free. A typical course runs between two and six sessions. The ketamine dose – 0.5mg per kilo of body weight – is administered by drip. A psychotherapist leads the patient through their trip. The aim, says Matrenitsky, is to tap subconscious traumas: “what we are doing is turning the memories into a metaphorical journey”.

“The soldiers were surprised at being able to return to the front lines so quickly … They simply didn’t think it was possible.”

Ihor Kholodilo, military psychologist and medic

He says about a third of his patients receiving ketamine enjoy “extremely good” results, and another third “reasonably good” ones. Bad reactions, usually panic attacks, are rare. That is the signal to stop the drip.

The doctor says most soldiers on the front lines would benefit from his treatment. He blames stigma and a “Soviet” approach to military medicine for slowing access, and is lobbying to make it more common. Another goal is to expand the treatment to include banned substances like MDMA and psilocybin (the active molecule in magic mushrooms).