Brain circuits involved in anxiety

The experience of anxiety is not a diffuse phenomenon, but is underpinned by the activity of specific neural circuits in the brain.

Understanding these circuits is critical to understanding how anxiety arises and how treatments can act to modulate it.

The Amygdala. The Fear Center

The amygdala, an almond-shaped structure located in the limbic system, plays a central role in the processing of emotions, especially fear and anxiety.

It acts as a threat detection system, quickly assessing stimuli in the environment for potential dangers.

When the amygdala perceives a threat (real or imagined), it triggers a cascade of physiological and behavioral responses associated with anxiety, such as activation of the sympathetic nervous system (fight-or-flight response).

In anxiety disorders, hyperactivity of the amygdala is often seen, meaning it may overreact to stimuli that are not objectively dangerous.

The Hippocampus and Fear Memory

The hippocampus, another structure in the limbic system, is crucially involved in the formation and consolidation of memory, including memories associated with fear and the context in which threats occurred.

It works closely with the amygdala.

If a particular situation was associated with an intense fear experience in the past, the hippocampus helps encode that contextual memory.

Later, being in a similar context can reactivate the fear memory and anxiety response, even if the original threat is no longer present.

The Prefrontal Cortex. Regulation and Control

The prefrontal cortex (PFC), especially its medial and orbitofrontal regions, plays a critical role in emotion regulation and decision-making.

It acts as a "brake" or modulator on the activity of the amygdala.

The PFC allows us to assess threats more rationally, consider the consequences of our actions, and suppress or regulate inappropriate fear responses.

In anxiety disorders, decreased activation or po