The effects of a powerful psychedelic drug are similar to a near-death experience, research suggests.

Answers to a questionnaire showed a "striking similarity" between people describing a near-death experience and volunteers given DMT.

The Imperial College London researchers concluded the near-death or "complex subjective" experiences had been caused by physical changes in the brain.

They now hope DMT can help them better understand the psychology of dying.

DMT is the major psychoactive compound in ayahuasca, a drink made from vines and used in some tribal ceremonies in South and Central America.

The 13 volunteers - who took DMT or a placebo - and the 67 who had reported having a near-death experience were asked questions including:

Dr Robin Carhart-Harris, who leads the psychedelic research group at Imperial College London and oversaw the study, said: "These findings are important as they remind us that near-death experiences occur because of significant changes in the way the brain is working, not because of something beyond the brain.

"DMT is a remarkable tool that can enable us to study and thus better understand the psychology and biology of dying."

Improving understanding of the neurobiology of dying "may have implications for how we view this most inevitable and universal phenomenon, potentially promoting a greater familiarity with and healthy acceptance of it", the authors added.

There were some subtle but important differences between the DMT and the near-death experience responses, however.

DMT was more likely to be associated with feelings of "entering an unearthly realm", whereas the the near-death experiences brought stronger feelings of "coming to a point of no return".

The authors caution that while the initial findings are interesting, they advise against self-medication with ayahuasca.

All volunteers were screened and overseen by medical staff throughout the study, published in Frontiers in Psychology.