Scientists have for the first time scanned the brains of people using LSD and found the psychedelic drug frees the brain to become less compartmentalised and more like the mind of a baby.

Key points: Brain in the LSD state is free and unconstrained, scientists say

Brain in the LSD state is free and unconstrained, scientists say LSD experience linked to "improvements in well-being" after the drug's effects subside, researchers say

LSD experience linked to "improvements in well-being" after the drug's effects subside, researchers say Finding "could have great implications for psychiatry"

A research team led by scientists at Imperial College London said that while normally the brain works on independent networks performing separate functions such as vision, movement and hearing, under LSD (Lysergic acid diethylamide) the separateness of these networks breaks down, leading to a more unified system.

"In many ways, the brain in the LSD state resembles the state our brains were in when we were infants — free and unconstrained," said Dr Robin Cahart-Harris, who led the study.

"This also makes sense when we consider the hyper-emotional and imaginative nature of an infant's mind."

The findings, published in Proceedings of the National Academy of Sciences (PNAS) journal, also showed that when the volunteers took LSD, many extra brain areas — not just the visual cortex — contributed to visual processing.

This could explain the complex visual hallucinations that are often associated with the LSD state, the scientists said.

Dr Carhart-Harris said the experience also seemed to be linked to "improvements in well-being" after the drug's effects subside, suggesting the findings may one day lead to psychedelic compounds being used to treat psychiatric disorders.

The drugs could be particularly useful in mental disorders where negative thought patterns have become entrenched, the scientists explained, such as in depression or addiction.

"For the first time, we can really see what's happening in the brain during the psychedelic state, and can better understand why LSD had such a profound impact on self-awareness," said Professor of neuropsychopharmacology David Nutt, who worked with Dr Carhart-Harris.

"This could have great implications for psychiatry."

Volunteers given injection of LSD or placebo

The Imperial team worked alongside the Beckley Foundation, a British-based group that backs scientific research into the potential medical benefits of psychoactive substances.

This study, funded by Beckley and by public donations through a crowdfunding platform, involved 20 healthy volunteers, each of whom received both LSD and a placebo, and all of whom were deemed psychologically and physically healthy.

All the volunteers had previously taken some type of psychedelic drug.

During controlled and supervised experiments in a specialist research centre, each volunteer was given an injection of either 75 micrograms of LSD, or a placebo.

Their brains were then scanned using various techniques, including functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG).

Using these techniques allowed the scientists to study activity in the whole brain by monitoring blood flow and electrical activity.

Reuters