fMRI brain scans show that psilocybin, the active ingredient in magic mushrooms, lowers the activity of specific brain regions. The finding contradicts the popular belief that psychedelic drugs increase brain activity, and has far reaching implications for the therapeutic use of psilocybin in the treatment of depression and cluster headaches, as well as throwing light on why it could be such a useful aid in psychotherapy.
Cutting edge research conducted by The Beckley Foundation-Imperial College Psychedelic Research Programme has produced surprising and exciting new findings on the effects of psilocybin on the brain.
The Beckley-Imperial Research Programme began in late 2009 after discussions between Amanda Feilding, Director of the Beckley Foundation, and Professor David Nutt, Professor of Neuropsychopharmacology at Imperial College London. Over the last 2 years the Programme has run the first series of scientific studies on psilocybin in the UK, and has been the first in the UK to use neuroimaging to study the effects of a psychedelic. The results of two separate Beckley-Imperial studies are to be published this week, one in PNAS –one of the most influential scientific journals in the US, and the other in the British Journal of Psychiatry. The exciting findings presented in the PNAS paper will arguably constitute the most important advance to date in our understanding of how psychedelic drugs work in the brain. Classic psychedelic drugs such as psilocybin induce a profound and distinctive change in consciousness. Unusual phenomena have been observed in this state, such as the recovery of repressed memories, a deep sense of connection with nature, lasting positive changes in mood and profound spiritual experiences.
The study published in PNAS used the latest fMRI technology to measure the effects of psilocybin on blood flow and brain activity. The project was conceived by Amanda Feilding and Professor David Nutt, and the principal investigator was Dr Robin Carhart-Harris.
To everyone’s surprise, the studies contradicted the assumption that psychedelics worked by increasing activity in the brain. The results showed that, in fact, psilocybin decreased brain activity in specific areas of the brain that act as ‘connector hubs’ –key junctions for information transfer such as the posterior cingulate cortex (PCC) and the medial prefrontal cortex (mPFC). These areas are known to show hyperactivity in depression, and it is possible that psilocybin may work in a similar way to antidepressant medications. This possibility opens up an exciting new line of research and suggests potential benefits and medical applications of the drug. The results were produced using the most advanced neuroimaging methods presently available, as well as rigorous statistical analyses. The results were internally replicated using two different fMRI modalities, which supports the validity of the conclusions. These modalities were BOLD (Blood Oxygen-Level Dependent, which measures brain activity via a blood flow related signal) and ASL (Arterial Spin Labelling, which measures changes in blood flow in the brain).
Commenting, Amanda Feilding, Director of the Beckley Foundation, initiator of the research and co-author of the papers, states: “Although the research comes up with the opposite results of what I had been expecting for the last forty years, I am very excited by it, as it not only gives us new insights into the nature of consciousness but also points the way to possible new treatments for depression and cluster headaches”.