The amygdala is a key structure in the brain that plays a significant role in the experience of anxiety. It’s important to understand its function to gain insight into why anxiety occurs and how it can be managed.
What is the Amygdala?
- The amygdala is a small, almond-shaped structure located deep within the brain. There are two amygdalae, one on each side of the brain.
- It is part of the limbic system, which is considered the “emotional brain”. The amygdala is not a “thinking brain” but a “feeling brain”.
- The amygdala acts as a fast-acting processor, picking up on important things, especially potential threats. It is essential for survival, quickly triggering responses to perceived dangers.
- The amygdala is responsible for attaching emotional significance to situations or objects and forming emotional memories. It can create both positive and negative emotional memories.
- It plays a crucial role in initiating the fight, flight, or freeze response, which is the body’s automatic reaction to perceived danger.
- The amygdala works very quickly, often before the thinking part of the brain (the cortex) has a chance to process the situation.
The Amygdala and Anxiety
- The amygdala is central to the creation of anxiety responses. It can initiate the physical experience of anxiety, such as a pounding heart, rapid breathing and muscle tension.
- Pattern matching: The amygdala uses pattern matching to identify potential threats. This process can be “sloppy” or “faulty”, leading to fear responses when there is no real threat. Faulty pattern matching is at the heart of many psychological problems, including anxiety.
- The amygdala can create emotional memories that lead to anxiety responses. These memories are not stored as images or verbal information but are experienced as emotional states.
- Triggers: When sensations, objects or situations have been associated with negative events, memories are stored in circuits that produce a negative emotion. These become triggers that can activate the amygdala’s alarm system.
- Amygdala activation occurs when constitutional features, traumatic experiences, or negative attachments have produced maladaptive emotion regulation. This restricts people in their ability to achieve emotional resilience and behavioral flexibility.
- Anxiety can arise through two pathways: directly through the amygdala or via the cortex (the thinking brain), which can activate the amygdala.
- Amygdala-based anxiety often feels like it comes out of the blue, creates strong physical reactions, and seems disproportionate to the situation.
- Amygdala hijack: When the amygdala identifies a threat, it can “hijack” the prefrontal cortex, inhibiting clear and rational thinking. This can lead to an inability to concentrate or direct attention.
- When the amygdala is in charge, the thinking brain goes offline which can push people out of their resilient zone and into a state of hyper or hypo arousal.
The Evolutionary Role of Anxiety
- Anxiety evolved to protect humans from physical harm and to help satisfy their physical and emotional needs. It’s an intrinsic part of the human condition.
- Anxiety is nature’s way of alerting people to the possibility of danger. All animals have the capacity to experience anxiety when they feel threatened.
- The purpose of anxiety is to demand attention and prepare the body for action. In appropriate situations, anxiety can save lives.
- The amygdala’s fear response is an ancient survival mechanism that has been passed down from early vertebrates. It is designed to respond to immediate threats with fight, flight, or freeze.
- Fear of things like snakes, spiders, and heights are thought to be biologically wired into the amygdala as a result of evolution.
Why Anxiety Seems Out of Control in the Modern World
- The amygdala operates on lessons learned in prehistoric times, still considering humans to be potential prey for other animals or humans. It can overreact in situations that are not truly dangerous.
- Although the daily dangers in our lives have been reduced since prehistoric times, the amygdala still activates the same fear responses, even when they are inappropriate.
- Faulty pattern matching: The amygdala is designed for speed and not accuracy. This is because reacting quickly to threats was essential for survival. In the modern world this can lead to inappropriate fear responses that feel out of control.
- Over-stimulation of the stress response: Modern life is often fast-paced and over-stimulating. This may cause the amygdala to trigger the stress response more often than is useful and overwhelm the prefrontal cortex.
- The human cortex is skilled at anticipating the future, so we feel potential future threats as if they’re happening right now.
- Social contagion: Anxiety is contagious and can be triggered simply by talking to someone else who is anxious.
- Modern life: The modern world presents unique challenges such as social pressure, financial stress, and constant exposure to information. These can contribute to chronic stress which over time can lead to anxiety disorders.
- The cortex: Although the cortex is widely presumed to be rational, it can also contribute to anxiety by over-analysing or anticipating future threats.
- Avoidance: When people try to avoid or control their anxious feelings, it can make things worse. For example, avoidance can prevent the amygdala from forming new connections.
Likely Causes of Increased Anxiety
- Brain chemistry: Imbalances and abnormalities in brain chemistry can make a person more susceptible to anxiety disorders.
- Traumatic experiences: Traumatic life events can lead to the development of anxiety disorders. Traumatic experiences may result in an overactive amygdala.
- Genetics: Genetics can influence the amygdala, and therefore typical emotional reactions. Children with a smaller left amygdala tend to have more anxiety difficulties.
- Maladaptive emotion regulation: Constitutional features, traumatic experiences, or negative attachments can lead to maladaptive emotion regulation.
- Increased sensitivity in the amygdala: There is evidence that people who suffer from anxiety and depression have an increased sensitivity in the amygdala.
- Lack of sleep: Lack of sleep can make the amygdala prone to more anxious responding.
- Chronic stress: Prolonged stress can enhance synaptic connectivity in the amygdala.
It is important to remember that although the amygdala can cause anxiety, it is not a “bad” part of the brain. It evolved to protect us. Gaining awareness of how the amygdala functions and how it contributes to anxiety is a first step to controlling anxiety rather than being controlled by it.
Understanding that both the amygdala and the cortex can contribute to anxiety can help people choose the best ways to manage their individual responses.