Why the Mind Gets Stuck—and How Psychedelics Might Unstick It
What “Canalization and Plasticity in Psychopathology” reveals about mental illness and change
https://www.sciencedirect.com/science/article/pii/S0028390822004579?via%3Dihub
Why do some thoughts, behaviors, and emotional patterns feel impossible to escape?
Why does depression repeat itself?
Why does addiction loop?
Why do certain beliefs feel fixed—even when they’re harmful?
In this recent theoretical paper, researchers—including Robin Carhart-Harris—propose a compelling answer:
The mind becomes “canalized”—locked into stable, self-reinforcing patterns.
And crucially:
Psychedelics may help break those patterns open.
The Core Idea: The Brain Forms “Ruts”
The concept at the center of this paper is canalization.
Think of it like this:
Water flows down a path
Over time, that path becomes deeper
Eventually, water has no choice but to follow it
The brain works similarly.
Over time:
Thoughts become habits
Habits become patterns
Patterns become rigid
This is useful for stability.
But it can become a problem when those patterns are:
Negative (depression)
Fear-based (anxiety)
Compulsive (addiction)
Two Types of Plasticity
The paper introduces a key distinction between two kinds of brain change:
1. Canalization (Stability)
Reinforces existing patterns
Makes behavior predictable
Associated with learning and habit formation
2. Entropic Plasticity (Flexibility)
Loosens existing patterns
Allows new connections to form
Associated with exploration and change
The authors call this second type:
“Temperature or Entropy Mediated Plasticity” (TEMP) (ScienceDirect)
The Problem: Too Much Stability
In healthy functioning, the brain balances:
Stability (to function)
Flexibility (to adapt)
But in many mental disorders, this balance breaks.
The system becomes over-canalized:
Depression → repetitive negative thinking
Addiction → rigid behavioral loops
PTSD → fixed fear responses
In these states:
The brain becomes too certain, too predictable, too stuck.
Psychedelics: Increasing Plasticity
This is where psychedelics enter the model.
According to the paper:
Psychedelics increase entropy-mediated plasticity—making the brain more flexible. (ScienceDirect)
In practical terms:
Neural pathways loosen
New connections become possible
Old patterns temporarily weaken
This creates a window:
A chance to reorganize the system.
Why Change Can Last
One of the most intriguing implications:
Psychedelics don’t just disrupt patterns—they may allow new ones to form.
Research suggests these substances can:
Increase brain connectivity
Promote neuroplasticity
Enable long-term psychological change (ScienceDirect)
This helps explain why:
A few sessions can produce lasting effects
Patients report “reset” experiences
The Role of Environment
But there’s a catch.
When the brain becomes more plastic, it also becomes more sensitive.
This means:
Context matters
Therapy matters
Environment matters
In this flexible state, the brain is:
More open to both positive change and negative influence.
This reinforces a core principle in psychedelic science:
Set and setting are not optional—they are central.
A New Model of Psychopathology
The paper proposes a broader shift in how we think about mental illness:
Instead of asking:
“What’s wrong with the brain?”
Ask:
“Is the brain too rigid—or too chaotic?”
This reframes disorders as problems of dynamical balance:
Too rigid → stuck
Too chaotic → unstable
Balanced → adaptive
Beyond Psychedelics
While psychedelics are a key example, this framework applies more broadly.
Other states may also increase plasticity:
Meditation
Flow states
Intensive therapy
All may temporarily:
Reduce rigidity
Increase openness to change
The Bigger Picture
This paper builds on earlier ideas like:
The entropic brain theory (flexibility of brain states)
Predictive processing (the brain as a model-builder)
But adds something new:
A model of how long-term patterns form—and how they can be broken.
Final Take
The mind is not just a processor.
It’s a system that learns—and sometimes gets stuck.
Canalization and Plasticity in Psychopathology offers a powerful insight:
Mental illness may not just be about dysfunction.
It may be about over-stability.
And recovery may not come from forcing change—
but from creating the conditions where change becomes possible.
R.L. Carhart-Harris, S. Chandaria, D.E. Erritzoe, A. Gazzaley, M. Girn, H. Kettner, P.A.M. Mediano, D.J. Nutt, F.E. Rosas, L. Roseman, C. Timmermann, B. Weiss, R.J. Zeifman, K.J. Friston, Canalization and plasticity in psychopathology, Neuropharmacology, Volume 226, 2023, 109398, ISSN 0028-3908,
https://doi.org/10.1016/j.neuropharm.2022.109398.