Ordinarily, when people take LSD, they're doing it recreationally, most often illegally – searching for a unique, personal high nobody else will have ever quite experienced.

But some of the time, they're actually doing it for science – and a new study that involved volunteers tripping under MRI scanners doesn't just tell us what's going on in the brain when people take acid: amazingly, it could also reveal new treatments for people with mental illness, such as schizophrenia.

That's because the findings are helping to clarify the neurological mechanisms behind the disembodiment and sense of 'oneness' people often say they experience when they're under the influence of LSDlysergic acid diethylamide.

While those high feelings are often characterised as transcendental or spiritual in nature by those who take LSD, scientists – armed with MRI data – have a somewhat different take on what's actually going on.

"Our interpretation is that LSD reduces your sense of integrated self," psychologist and neuroscientist Katrin Preller from the University of Zurich explained to The Guardian.

"In this particular case, the drug blurs the boundary between what is you and what is another person."

That conclusion is based on an unusual experiment with 24 healthy people who were randomised to voluntarily take either LSD, a placebo, or LSD in conjunction with ketanserin, which blocks the effects of LSD in the brain.

While dosed with their mystery substance, these participants lay under an MRI scanner wearing digital goggles, and engaged in an exercise where they had to either make eye contact or follow the gaze of a virtual avatar in their field of vision.

The game was used as a proxy for social interaction, but depending on the dose people took, not everybody was on the same playing field.

Those under the influence of straight LSD showed reduced neural activity in the posterior cingulate cortex and the temporal cortex, brain areas that help determine one's sense of self.

Participants who had received a placebo or the LSD and ketanserin combination didn't demonstrate this, with the chemical 'antidote' effectively negating the self-distorting effects of their acid trip.

"It gets rid of this blurring between self and other, and the basic deficits in social interaction go away," Preller said.

If you're wondering what all this has to do with treating conditions like schizophrenia, it's this: in the experiment, there was no significant difference in performance during the avatar game between the group who took the placebo and the group who took LSD with ketanserin.

Basically, their results looked the same.

That's an important thing to note, because the way ketanserin disrupts the effects of the psychedelic is by blocking what's called the serotonin 2A receptor (5-HT2A receptor).

Knowing that this receptor is somehow vital to regulating or maintaining the 'sense of self' in healthy brains could turn out to be a major discovery for helping to understand why people with mental illness don't have this self-aware way of thinking, and experience difficulty with social interactions as a result.

Now, we have a new target for therapeutic interventions.

For people who may already experience a distorted, disembodied sense of self without taking LSD – purely because of their brain chemistry – that could make all the difference.

"Healthy people take having this coherent 'self' experience for granted," Preller told Live Science, "which makes it difficult to explain why it's so important."

The findings are reported in the Journal of Neuroscience.