A major Australian study has found that nitrous oxide — commonly known as laughing gas — may offer new hope for people suffering from treatment-resistant depression.
The trial, led by Monash University professors Paul Myles and Jayashri Kulkarni, involved 81 Victorian adults whose depression had not responded to standard treatments. Often linked to past trauma, this type of drug-resistant depression is more prevalent among women and can severely impact quality of life.
The results, described as “striking,” showed that after just four one-hour sessions, 20 per cent of participants experienced full remission, while another 20 per cent reported a significant reduction in symptoms.
Professor Myles, a leading anaesthetist and research director at The Alfred Hospital, shared the findings at the Australian and New Zealand College of Anaesthetists’ annual meeting in Cairns. He said the results were encouraging for a group of patients who often live “sad and debilitating lives.”
“We had people saying, ‘For the first time I could see colours,’ or ‘I finally have an appetite for life,’” he said.
During the sessions, patients inhaled a carefully controlled dose of nitrous oxide while sitting and listening to music under close supervision. The gas, long used as an anaesthetic, was administered in a way designed to prevent side effects or abuse.
Professor Kulkarni, from the Monash Alfred Psychiatry Research Centre, said the study opens the door to new ways of understanding and treating depression. “It’s not just about another drug. It’s about rethinking what’s happening in the brain,” she said.
The findings have been published in *Biological Psychiatry*. The researchers now hope to launch a larger-scale trial, saying the evidence so far suggests nitrous oxide could become a valuable new tool in mental health care.
