Since its discovery in 1938, the drug LSD — that's lysergic acid diethylamide — has puzzled researchers. They knew the drug had a profound effect on people, causing hallucinations and an altered state of consciousness, but they couldn't figure out why.
Now that could be changing.
A research team from the University Hospital of Psychiatry Zurich thinks it's figured out what's going on in the brain when someone "trips" — and the discovery could play a major role in future research on psychiatric disorders.
For their study, which was published in the journal PNAS on Monday, the researchers gave 25 volunteers LSD while scanning their brains.
They also gave some of those volunteers ketanserin, a drug that blocks serotonin receptors. Serotonin is a neurotransmitter previously suspected of playing a role in the LSD experience.
When the researchers had the volunteers answer a questionnaire designed to determine whether someone is "tripping", they found that the people who took the ketanserin experienced none of the subjective drug effects of the LSD.
Another intriguing result was that the scans revealed that the LSD interrupts a major circuit between four parts of the brain, including the thalamus, which acts as an information filter.
Essentially, the drug allowed more information to flow through the thalamus to other parts of the brain.
Now that we have a better understanding of how LSD affects the brain, researchers believe they can use that information to study disorders that produce the same effects as the drug, such as depression and schizophrenia.
"We are getting nearer to understanding the complexity of what happens with LSD in the brain," researcher Katrin Preller told The Guardian, "and that is particularly important if we are to develop new medicines."