Psilocybin and meditation have same effect on posterior cingulate cortex

PTSD, Mindfulness and Psilocybin's name was derived from the insight that mindfulness and the after-effects of psilocybin share similar qualities which would be of great benefit to those suffering from PTSD or from other existential crises. This website was created prior to fMRI studies delineating psilocybin's effects on the brain which is now known to include a decrease in activity of the posterior cingulate cortex (PCC).  Recently, I have become aware of fMRI studies showing a similar decrease in PCC activity with various forms of meditation and prayer which has been a pleasant surprise.

The PCC exhibits connectivity with a wide range of intrinsic control networks. Its most widely known role is as a central node in the default mode network (DMN). The default mode network (and the PCC) is highly reactive and quickly deactivates during tasks with externally directed, or presently centered, attention (such as working memory or meditation). Conversely, the DMN is active when attention is internally directed (during episodic memory retrieval, planning, and daydreaming). A failure of the DMN to deactivate at proper times is associated with poor cognitive function, thereby indicating its importance in attention. Increased size of posterior ventral cingulate cortex is related to the working memory performance decline. (Wikipedia: posterior cingulate cortex)

A recent article "What about the “Self” is Processed in the Posterior Cingulate Cortex?" (Front Hum Neurosci. 2013; 7:647.) highlights the following functions the PCC is involved with:

• the PCC functions to evaluate or judge how one relates to one’s experience: how much they are caught up in it

• Recent work in cognitive neuroscience has demonstrated a role for the PCC in social processing, such as mentalizing, evaluative judgments, and sensitivity to moral issues

• the PCC, among other regions, was more strongly activated for actions leading to harm to others relative to oneself, and suggest that actions involving guilt may lead to greater preoccupation with self-actions rather than thoughts about harm caused to others.

• (increased) PCC activity has been associated with poorer task performance

• Craving, perhaps one of the most obvious experiences of being caught up in experience, is described clinically and experimentally in terms of desire, urge, want, and need ... it has been associated with PCC activity in smoking and drug addiction

• PCC activity decreases when one becomes less caught up in ones experience

• decreased coupling between the PCC and mPFC with psilocybin corresponds with the subjective experience of a less egoic state, or less “self.”

Another recent article, "Disrupting posterior cingulate connectivity disconnects consciousness
from the external environment" (PDF) (Neuropsychologia Volume 56, April 2014, Pages 239–244), describes the results of surgery in which part of the PCC, precuneus and retrosplenial areas were resected in a patient with a slow-growing lesion in the left posteromedial cortex. The surgeons reported "the patient reported experiencing no rumination for almost a month after the surgery and to be in a contemplative state with a subjective feeling of absolute happiness and timelessness."  They concluded "this finding provides support to the view that the posterior cingulate is a pivotal hub within the brain's functional architecture."

Mindfulness meditation addresses all of the above functions as it encourages openness, being non-judgemental, promotes attentive awareness and results in a more universally connected, less egoic mindset.  However, since mindfulness may not be easily obtained by many, what other option exists to provide a similar result?  The answer is of course therapeutic administration of psilocybin taken with the proper mindset and in a supportive environment.  As Roland Griffiths from Johns Hopkins has stated:

If meditation represents the systematic "tried and true course" of discovery of the nature of mind and Self, psilocybin represents the "crash course"

It is time for  the Department of Defense and the Veterans Administration ("We must do all we can to deliver the high-quality care our service members and veterans have earned and deserve.”) to stop talking the talk about trying to do everything they can to treat PTSD and to start walking the walk by leading the way in initiating Clinical Trials utilizing psilocybin in a therapeutic setting to treat PTSD.

A 2015 article in the European Journal of Psychotraumatology titled:
Restoring large-scale brain networks in PTSD and related disorders: a proposal for neuroscientifically-informed treatment interventions
Increasing evidence for altered functioning of the central executive, salience, and default mode networks in PTSD has been demonstrated. We suggest that each network is associated with specific clinical symptoms observed in PTSD, including cognitive dysfunction (central executive network), increased and decreased arousal/interoception (salience network), and an altered sense of self (default mode network). Specific testable neuroscientifically-informed treatments aimed to restore each of these neural networks and related clinical dysfunction are proposed.
Lanius RA, Frewen PA, Tursich M, Jetly R, McKinnon MC.
Eur J Psychotraumatol. 2015 Mar 31;6:27313. doi: 10.3402/ejpt.v6.27313. eCollection 2015.
PMID: 25854674
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