Fibromyalgia and the Brain: A New Model of the Painful Self
Fibromyalgia is a chronic condition that affects how the body processes pain. It’s defined by widespread musculoskeletal pain, fatigue, non-restorative sleep, cognitive issues (often called "fibro fog"), and significant emotional distress. There is no single cause and no universal treatment, but brain imaging research is offering new insight into what might be happening under the surface.
A recent 2025 meta-analysis by Cavicchioli and colleagues provides one of the most detailed pictures to date of how brain connectivity may help explain the persistent and often overwhelming experience of fibromyalgia. Their work introduces an innovative theoretical approach by integrating two well-established brain models: the nested hierarchical model of self and the pain matrix.
The Innovation: Bringing Two Models Together
What sets this study apart is its attempt to understand fibromyalgia through the interaction of self-awareness and pain processing in the brain.
The Nested Hierarchical Model of the Self
This model describes how our brain constructs a sense of self through three layers:Interoceptive self – awareness of internal sensations like heartbeat, pain, and gut tension.
Exteroceptive/proprioceptive self – awareness of where the body is in space and how it interacts with the world.
Mental self – thoughts, memories, and the narrative sense of identity.
The Pain Matrix
This refers to the network of brain regions involved in detecting, modulating, and interpreting pain signals. It includes the thalamus, somatosensory cortices, insula, anterior cingulate cortex (ACC), and the periaqueductal gray (PAG), which plays a key role in pain inhibition.
By combining these models, the researchers created a comprehensive framework for understanding fibromyalgia as a disorder of both sensory processing and self-related neural activity.
What the Researchers Did
The authors conducted a meta-analysis of 11 fMRI studies using resting-state functional connectivity (RS-FC) in patients with fibromyalgia compared to healthy controls. Resting-state imaging captures how different brain regions communicate when a person is not engaged in any specific task — a useful tool for understanding baseline brain activity and network dynamics.
They specifically looked at:
Connectivity within and between self-related brain regions
Connectivity within the pain matrix
Associations between brain connectivity patterns and reported pain intensity
What They Found
1. Increased connectivity between self-related regions
Fibromyalgia patients showed stronger-than-normal communication between the default mode network (DMN) — a major hub of the mental self — and areas involved in interoception (e.g. insula, ACC) and exteroception (e.g. visual and auditory cortices, premotor cortex). This pattern suggests that these individuals may be more internally focused and highly sensitive to body signals, even at rest.
2. Reduced connectivity within the pain matrix
Connectivity between the periaqueductal gray (PAG) and somatosensory areas was reduced in fibromyalgia patients. These are key areas for pain modulation, and their weakened communication suggests a decreased ability to downregulate pain signals.
3. Link between self-related connectivity and pain intensity
The more strongly connected the DMN was to interoceptive areas, the higher the pain intensity reported by patients. This suggests that the more closely body awareness is tied into the brain’s core self-processing system, the more pain is amplified.
What This Tells Us About Fibromyalgia
The findings support the idea that fibromyalgia is not just about hyperactive pain signals, but also about how the brain organizes and relates to those signals as part of the self.
Patients may experience their pain as deeply personal and persistent not only because of sensory input, but because their brain’s self-model integrates that pain into their identity and bodily awareness. In other words, pain becomes part of how the body is sensed and how the self is constructed.
This may also explain the frequent co-occurrence of mood disorders, dissociative symptoms, and identity-related distress in people with fibromyalgia.
Treatment Implications
The authors suggest that targeting the brain networks involved in self-processing and pain regulation could offer more effective treatment options.
Therapeutic approaches with the potential to influence these systems include:
Mindfulness-based interventions: These may reduce hypervigilance toward bodily sensations and encourage a decentered awareness of experience, potentially altering DMN-insula connectivity.
Acceptance and Commitment Therapy (ACT): ACT emphasizes the idea of the “self-as-context,” which may help reduce the fusion between the experience of pain and one’s core identity.
Movement therapies: While aerobic exercise has long been a staple recommendation, interventions like gentle resistance training or somatic movement may also support proprioception, interoception, and pain modulation.
Breathwork and meditation: Practices that improve interoceptive accuracy and regulate autonomic tone may help address the altered brain-body signalling seen in fibromyalgia.
These strategies are not simply about distraction or symptom suppression. They work by gradually reorganizing brain networks — including those that govern pain, body awareness, and identity.
Conclusion
This study provides important support for a biopsychosocial model of fibromyalgia rooted in contemporary neuroscience. Rather than treating pain and psychological distress as separate domains, it offers an integrated view in which self-awareness, body regulation, and pain perception are all part of the same neural story.
By understanding fibromyalgia in this way, clinicians can better support patients through interventions that aim not only to reduce pain but also to reshape the brain networks that make that pain feel so constant, personal, and overwhelming.
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Cavicchioli, M., Scalabrini, A., Nimbi, F., Torelli, A., Bottiroli, S., Pichiecchio, A., Prodi, E., Trentini, C., Sarzi-Puttini, P., & Galli, F. (2025). Fibromyalgia and the painful self: A meta-analysis of resting-state fMRI data. Journal of Psychiatric Research, 183, 61–71. https://doi.org/10.1016/j.jpsychires.2025.01.048
