The Neuroscience of CBT for Anxiety and Trauma

By Tara Kearns

Cognitive Behavioural Therapy (CBT) is widely recognized for its effectiveness in

treating mental health difficulties including anxiety, trauma, and depression.

However, neuroscience research shows that CBT not only changes thoughts and

behaviours; it also brings about real and measurable changes in brain function.

In people with chronic anxiety or trauma, the brain’s alarm system - the amygdala - is

over sensitive and constantly alert. This leads to hypervigilance- a feeling of being

continuously on edge as a consequence of incessant scanning of the environment

for threats. These threats can be actual- like an angry email from a coworker, or

imagined- like the thought of losing your job. Hypervigilance drives an exaggerated

threat response, which can cause us to feel anxious or afraid - even when there is no

threat present.

The amygdala’s job is to keep us safe; to detect threat and to trigger the body’s fight

or flight response in order to escape or ward off danger. In order to do its job well,

the amygdala needs to work fast. So, the amygdala processes information quickly-

and is much faster than the brain’s logical decision-making centre, the prefrontal

cortex. This is why we often feel fear or anxiety before we know why.

The prefrontal cortex helps to regulate the amygdala by evaluating the situation and

deciding whether the threat detected is serious or real. However, when we are

chronically stressed, our prefrontal cortex becomes less active, which reduces our

ability to self-regulate and think clearly. So, an oversensitive amygdala and a stressed pre-frontal cortex lead to a negative cycle of hypervigilance and anxiety.

CBT helps to rebalance these systems by desensitising the amygdala using breathwork, grounding and exposure techniques; and strengthening the prefrontal cortex’s ability to regulate the amygdala by training us to recognise, challenge and reframe unhelpful thoughts.

Brain imaging studies show that CBT is associated with increased activity in the prefrontal cortex and decreased activation of the amygdala, leading to a calmer mind and reduced anxiety.