Understanding the discussion about Polyvagal Theory

You may have heard of Polyvagal Theory, a framework that seeks to explain how our nervous system responds to experiences of safety and threat. It has been widely used by therapists to help people understand how trauma can affect the body, emotions, relationships and sense of safety.

Recently, some scientists have raised questions about aspects of the theory, particularly some of its biological explanations. This has prompted discussion about which parts of Polyvagal Theory are supported by current evidence, and which remain debated.

At its core, Polyvagal Theory describes different patterns of response that may occur as we experience and respond to the world around us.

For example:

• when we feel safe enough, we may feel calm, connected and able to think clearly
• when we sense threat or danger, our body may prepare to fight or escape
• when things feel overwhelming or we cannot escape, we may feel frozen, numb or disconnected.

Some researchers are questioning whether particular biological explanations proposed by Polyvagal Theory are supported by current neuroscience.

In particular, researchers have raised questions about:

• whether certain vagus nerve pathways work in the way the theory proposes
• whether heart rate patterns reflect nervous system activity in the way the theory suggests
• whether the evolutionary explanations underpinning the theory are supported by current evidence.

These questions do not mean that Polyvagal Theory has no value. Rather, they invite us to distinguish between its usefulness as a framework for understanding and talking about human responses to safety and threat, and some of the specific biological explanations proposed by the theory. (references)

Questions about aspects of Polyvagal Theory do not change the broader evidence that trauma can affect the body and nervous system.

A substantial body of research shows that:

• trauma can affect how the nervous system functions
• our bodies can respond automatically to perceived threat
• experiences of safety and supportive relationships can help us regulate our emotions and responses
• over time, people can develop greater capacity to regulate and respond to stress.

It is important to distinguish between the broader understanding of trauma and the specific theories we use to explain it.

Polyvagal Theory remains a useful framework for many people and practitioners. It can provide accessible language for understanding experiences of safety, threat, connection and disconnection, and has contributed significantly to trauma-informed thinking and practice.

At the same time, finding a framework useful does not mean that every scientific explanation underpinning it has been established. Our understanding of the brain, body and nervous system continues to develop as new research emerges.

Discussing the evidence openly allows us to retain what is helpful, reconsider what may need updating, and ensure that the information and practices we share continue to be informed by the best available evidence.

If you have experienced anxiety, shutdown, dissociation or feeling constantly on alert, these are real responses experienced by many people impacted by complex trauma. They can reflect ways our bodies and minds respond to overwhelming experiences and perceived threat.

Understanding these responses can help us approach ourselves with greater compassion and learn ways to support regulation and recovery.

Regardless of which scientific model is used, one important message remains: