Future Directions for Clinical Psilocybin Research: The Relaxed Symptom Network
This paper proposes the "Relaxed Symptom Network" hypothesis: psilocybin-assisted psychotherapy (PAP) reduces depression by weakening connections between symptoms within a dynamic symptom network, thereby lowering vulnerability to relapse. It outlines how applying network theory can clarify PAP's mechanisms and gives practical guidance for future clinical trials.
Abstract
Objective
Recent clinical trials have demonstrated that psilocybin may have strong antidepressant effects, and may be effective in the treatment of depressive disorders when embedded in a psychotherapeutic protocol (psilocybin-assisted psychotherapy; PAP). However, despite promising results, the mechanism(s) that may be responsible for the antidepressant effects of PAP remain contested. Within this article, it is argued that the ‘Network Theory of Mental Disorders’ may be a useful tool for clinical research with psilocybin, and may help elucidate the antidepressant elements of PAP.
Method
The clinical research using PAP for depressive disorders is briefly summarised, as are the potential mechanisms of PAP. In addition to this, the fundamental tenets of the network theory is presented, with particular reference to depression. In brief, the network theory proposes that depression is an emergent phenomenon, due to strong interactions in a complex dynamic symptom network.
Results
A model of action based on a symptom network is proposed. It is hypothesised that, if PAP is successful, the connections between symptoms in a network will weaken, thereby rendering the patient less vulnerable to developing/relapsing into depression. It is argued that the application of the network theory may ultimately improve responsiveness and reduce relapse in PAP. Practical guidance in using the network theory for future clinical research with psilocybin is also provided.
Conclusion
This article presents the primary hypothesis of the authors (The Relaxed Symptom Network), and intends to inform future researchers on how to integrate the network theory with future clinical studies using PAP.
Research Summary of 'Future Directions for Clinical Psilocybin Research: The Relaxed Symptom Network'
Introduction
Classic psychedelics such as psilocybin, LSD and DMT act primarily at the 5-HT2A receptor and produce marked changes in brain functional organisation alongside altered mood, perception and cognition. Recent clinical trials of psilocybin-assisted psychotherapy (PAP) have reported very large within-participant effects for depressive disorders, and at the time of writing there were 88 registered trials investigating psilocybin for a range of mental health conditions. Despite this renewed clinical interest, the mechanisms by which PAP produces antidepressant effects remain contested and many trials are small, often lacking rigorous placebo control or large samples needed to determine true effect sizes and relapse risk. Lewis-Healey and colleagues propose integrating the Network Theory of Mental Disorders into clinical research on psilocybin. Rather than treating depression as a latent construct that causes symptoms, the network approach models psychopathology as directly interacting symptoms. The primary hypothesis advanced here is that effective PAP will weaken the connections between symptoms in a person’s depression network, producing a ‘‘relaxed symptom network’’ that reduces vulnerability to relapse. The paper outlines how applying network methods could clarify mechanisms, personalise treatment (for example by identifying central symptoms to target during a session), and improve relapse prediction and monitoring in PAP research.
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Lewis-Healey, E., Laukkonen, R. E., & van Elk, M. (2021). Future Directions for Clinical Psilocybin Research: The Relaxed Symptom Network. https://doi.org/10.31234/osf.io/q3ymd
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