Rasika Karkare 
Anxiety is a common emotion, everyone experiences it from time to time, be it before an important presentation or meeting someone on a date. Normally, anxiety goes away once the stressful situation is over. However, this anxiety can be persistent and quite nagging for those who have an anxiety disorder.
But have you wondered why normal anxiety and anxiety disorder are so different? What happens in the brain if someone suffers from an anxiety disorder? Anxiety disorders not only affect the body and mind but can also have a significant impact on the brain, especially in the long run. In this article, we'll discuss some key differences between an anxious brain and a normal brain, as well as how long-term anxiety impacts the function and structure of the brain.
Short-Term Changes: Anxious Brain vs Normal Brain
Amygdala
The amygdala is an almond-shaped structure in the brain, responsible for processing emotions, fear and anxiety in particular. That is why it is also known as the fear centre of the brain, In an anxious brain, the amygdala is usually hypersensitive, leading to an exaggerated response to even minor threats or non-threatening situations. In contrast, a normal brain has balanced activity in the amygdala, leading to balanced emotional reactions instead of exaggerated fear. Research has also shown that the size of the amygdala is larger in brains with anxiety as compared to normal brains.
Hippocampus
The hippocampus plays a crucial role in the formation of new memories and also in the recall of old ones. The hippocampus can be severely affected in people with anxiety. Research and brain imaging suggest that chronic stress and anxiety can cause the hippocampus to shrink in size, impairing its ability to process memories effectively. Additionally, anxiety can make it harder for the hippocampus to recall positive memories, leading to the brain getting stuck in negative memories that increase the anxiety. In a normal brain, the hippocampus can recall positive events appropriately as per context.
Pre-frontal cortex (PFC)
The PFC is responsible for higher-order cognitive functions such as decision-making, problem-solving, and emotional regulation. Within the PFC, there is another small region called the ventrolateral prefrontal cortex (VLPFC) which is responsible for regulating the fear signals coming from the amygdala, leading to rational response and emotional regulation. However, in an anxious brain, there is an impaired connection between the PFC and the amygdala, leading to difficulties in emotional regulation.
Anterior Cingulate Cortex (ACC)
The ACC is a part of the brain involved in the detection of pain. It also plays a crucial role in emotional processing. Impulse control and error detection. In an anxious brain, the ACC becomes hyperactive. This hyperactivity can lead to an increased perception of threat, fueling constant worry and negative thoughts, which further leads to a state of hypervigilance in people with anxiety, Conversely, the ACC functions in a balanced way in normal brains.
Neurotransmitters
You might have heard that anxiety can sometimes be caused by a chemical imbalance in the brain. Neurotransmitters are brain chemicals. that transmit signals across the brain. In an anxious brain, there are often imbalances in key neurotransmitters such as serotonin, norepinephrine, and gamma-aminobutyric acid (GABA). Serotonin is often low in people with anxiety. Norepinephrine is responsible for the body's fight-or-flight response and high levels of norepinephrine are often associated with anxiety Similarly, reduced GABA activity is associated with anxiety.
Long-Term Effects of Anxiety on the Brain
While the short-term differences between an anxious brain and a normal brain are significant, chronic anxiety can have even deeper, long-lasting impacts on brain structure and function.
Anxiety and Amygdala
Research suggests that chronic anxiety affects the functioning of the amygdala. Anxiety often causes the amygdala to be enlarged. This enlargement causes the amygdala to become hyperactive in stressful situations. This heightened sensitivity can create a vicious cycle, where even minor stressors trigger intense fear responses.
Over time, hyperactivity in the amygdala can contribute to increased anxiety symptoms, making people susceptible to panic attacks and other anxiety symptoms.
Anxiety and Hippocampus
Chronic anxiety can reduce the volume of the hippocampus, causing it to shrink in size. This shrinking can lead to impairments in the workings of the hippocampus. Impairments in the hippocampus can cause problems in memory, leading to difficulties in remembering old information and the formation of new memories.
The hippocampus is also responsible for connecting memories with the locations where they occurred. This explains why people with anxiety disorders may avoid specific places because they connect them with negative experiences from the past.
Anxiety and Stress Hormones
The sympathetic nervous system in the body plays a crucial role in anxiety. It is responsible for responding to stressful situations. During stress, the sympathetic nervous system releases hormones like cortisol and adrenaline to make the body ready for incoming difficulty. Once the stressful situation is over, the parasympathetic nervous system calms the body down**. However, for people with chronic anxiety, the stress hormones continue to be released even after the danger is over. Increased cortisol levels can slow down the process of neurogenesis (the formation of new neural pathways)**
Anxiety and Pre-Frontal Cortex
Chronic anxiety can cause the PFC to be small and underactive, impairing its functioning. Impaired PFC function can lead to problems with decision-making and rationalizing. It can also lead to difficulties with emotional regulation. Additionally, anxiety can disrupt the connection between the PFC and the amygdala, causing difficulties in rational thinking, which can make it even more difficult to deal with anxiety, creating a vicious cycle.
Anxiety and the Anterior Cingulate Cortex (ACC)
Anxiety can increase activity in the ACC, leading to increased emotional reactivity and difficulties in emotional regulation. Increased activity can also lead people to experience intense and prolonged emotional reactions to stressors, feeding further into pre-existing anxiety.
Conclusion
Anxiety is a complex condition that can cause changes in the inner workings of the brain. Thus, an anxious brain differs from a normal brain in various aspects, such as the size of the amygdala and hippocampus and also neurotransmitters. Research suggests that chronic anxiety can have a lasting impact on the structure and functioning of the brain, impacting areas related to attention, memory, decision making and emotional regulation.
However, the good news is that early detection and treatment through medication, therapy, and lifestyle changes can help manage these effects. The anxious brain can start returning to normalcy through various anxiety treatments, such as Cognitive Behaviour Therapy (CBT) or medication. So, if you are someone struggling with anxiety, don't hesitate to seek help.
References
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