Anxiety Unpacked

 Introduction

Have you ever had to give a big, important speech or presentation in front of a room full of people? Did you feel like your heart was pounding, palms becoming sweaty & your mind going blank? This horrible feeling isn’t just stage fright, but also a sign of anxiety. According to Medline Plus, anxiety is a feeling of “fear, dread, and uneasiness” that can cause one “to sweat, feel restless and tense, and have a rapid heartbeat” (MedlinePlus, 2023). 

Furthermore, anxiety doesn’t only arise during distressing events (trauma, car accidents, etc.), but they can also occur easily during daily, normal situations as well. For instance, one might feel anxious ordering food at a restaurant, talking to their boss or meeting someone new for the first time. Because of how easily it can arise, anxiety disorders have become “the most common mental illness in the U.S., affecting 40 million adults” (ADAA 2022). 

But, what's the root cause of this overwhelming feeling? The answer lies in the inner workings of the brain. Research has shown that anxiety isn't only rooted psychologically, but also biologically through the brain’s pathways & structures. So, let’s explore this even further!

Key Concepts

To understand anxiety, we first need to learn more about the brain functions, systems & structures.  Each of these components play a significant role in the formation of anxiety: 

• Amygdala: a small, almond-shaped structure in the brain & is the main emotional processing center of the brain

  • The amygdala plays a primary role in regulating the emotions for fear & anxiety because they are able to detect danger for survival.

• HPA Axis (Hypothalmic-pituitary-adrenal Axis): a complex system in the body that involves the hypothalamus, pituitary gland & adrenal glands to formulate a response to stress or fear through a negative feedback loop:

  • When someone first encounters a stressor (trauma, injury, relationships problems, etc.), the hypothalamus senses this & releases the corticotropin releasing hormone (CRH)

  • The released CRH stimulates the pituitary gland to release the adrenocorticotropic hormone (ACTH)

  • The released ACTH travels through the blood & reaches the adrenal glands, which then releases cortisol

  • This released cortisol from the adrenal glands then causes the hypothalamus & pituitary glands to reduce the release of CRH & ACTH respectively, producing a negative feedback loop (Moller, 2019)

  • The reduced CRH & ACTH levels causes the body to go from a stressed state to a rested state

            The picture above is a diagram of the HPA Axis: shows the negative feedback loop of the 3                 different hormones from the hypothalamus to the pituitary gland & then to the adrenal gland

•  Prefrontal Cortex (PFC): a region of the brain that’s responsible for higher-level cognitive functions (decision-making, regulating one’s personality, social perception, emotion regulation, etc.)

• Neurotransmitters involved with Anxiety (Cleveland Clinic, 2024)

  • GABA: the main inhibitory neurotransmitter in the brain; functions by blocking signals between the brain & spinal cord, which causes the brain to slow down & the body to relax

  • Serotonin: a monoamine neurotransmitter that’s known to regulate mood & emotions; known to be the body’s  “feel-good” chemical & released during positive & negative experiences, which helps produce the body’s reward & punishment respectively

• Generalized Anxiety Disorder (GAD): a condition characterized by severe & excess anxiety that interferes with everyday life. 

  • A person would be diagnosed with GAD if they’ve felt this excessive worry for at least 6 months & displayed specific symptoms: excessive worry, difficulty concentrating, restlessness, fatigue, etc.

    
    
    
    
    
    Analysis

    It wasn’t until 1980 that anxiety was classified as a disorder under the Diagnostic and Statistical Manual of Mental Disorders (DSM-III). Since that time, scientists & psychologists have made many significant discoveries understanding anxiety, allowing us to gain greater insight into the various biological factors that play a role in the development of anxiety. Let’s explore these factors through the more recent studies that have been conducted:

    The Amygdala & the Prefrontal Cortex Connectivity

    According to a NIH (National Institute of Health) article about the various neurobiological mechanisms that can influence GAD, there was a study conducted to explore how certain brain regions & their connectivity, or lack thereof, could influence the development of GAD. In this study, a group of adolescents & adults with GAD (GAD group) & the participants without GAD (healthy control group) were formed to explore the differences in the connectivity of brain regions by using neuroimaging. 

    From the scans, the researchers discovered that there was less connectivity between the amygdala & the PFC for the GAD group, compared to the control group. (Patriquin, 2017). Because these 2 structures are known to process & regulate emotions, it was concluded that the fear & emotional dysregulation during anxiety would be a result of this disconnectivity. 

    The Influence of the Chemical Messenger, GABA

    Along with the structures of the brain, neurotransmitters can also play a crucial role in the development of anxiety. According to an article in the Nature Portfolio Journal (NPJ), a study was conducted to investigate how the neurotransmitter GABA can influence anxiety. The researcher used 2 groups of mice: a group of mice with anxiety (treatment group) and a group of healthy mice (control group). During this study, the mice performed maze & open-field tests before & after the study to evaluate the effect of GABA for the treatment group’s anxiety. After 2 weeks of the mice taking oral GABA, they were then assessed through the open-field tasks to determine whether the oral GABA has any effect on the mice’s anxiety. 

    The results that compared the open field tests before & after helped the researchers determine that oral GABA “signficantly alleviated anxiety-like behaviors” in the treatment group and caused “increased GABA levels in the prefrontal cortex, and elevated anti-inflammatory factors” (Xu, 2025). These findings led researchers to conclude that GABA helped alleviate anxiety by modulating the neuroinflammatory response in the brain. 

    Real World Applications

    Along with the miraculous discoveries over the years, researchers & scientists have discovered ways to apply their findings & develop treatments, ranging from therapuetic to pharmacological. Let’s explore some of the many treatments developed for anxiety! 

    • Cognitive Behavioral Therapy (CBT)

      • What is it: a form of therapy that’s been known to treat a variety of mental health conditions (anxiety, depression, eating disorders, etc.) by having a client challenge their negative thoughts & identify harmful behaviors. 

        • Throughout the treatment, the client learns to identify & develop their negative thoughts & actions into positive acts & coping mechanisms. 

        • As a result, the client experiences improved emotional regulation, reduced symptoms & a greater sense of control over themselves

      • Drawbacks

        • Emotional discomfort: clients may be instructed to be put in situations that are forced to bring their negative thoughts & emotions forward. During these types of sessions, the client may struggle or feel physically drained afterwards

        • Consistent commitment & participation: CBT is a long-term treatment that lasts for at least a couple of months & requires consistent participation from clients. For instance, clients in CBT are expected to attend their sessions regularly & complete tasks that are assigned by their therapist outside of the session (Corliss, 2024)

An illustration of Cognitive-Behavioral Therapy between a client & a psychologist

Medications

    SSRIs (Sustained Serotonin Reuptake Inhibitors)

• • • What is it: a class of medications that increase serotonin levels in the brain

    • How do they treat anxiety: anxiety can be caused by low levels of serotonin, which can lead to the misregulation of mood & emotions. So, SSRIs ability to increase serotonin, leads the brain to gain a better control over regulating the body’s emotions, as well as its fear

    • Drawbacks:

      • Side Effects: insomnia, rashes, headaches, muscle pain, an upset stomach, etc.

        Benzodiazepines

  • • What is it: a class of medications that increase GABA levels in the brain

    • How do they treat anxiety: studies have shown that low levels of GABA can be a factor towards anxiety since the low levels lead to neuroinflammation in the brain. So, when benzodiazepines increase the levels of GABA, it modulate the neuroinflammation & prevent anxiety symptoms

    • Drawbacks

      • Side Effects: drowsiness, dizziness; may lead to addiction, dependence or withdrawal symptoms

        Conclusion

        Anxiety is a complex mental condition that affects nearly 20% of the population in the U.S. & is the most prevalent mental health disorder. The origin of this condition involves connections between various brain structures—like the amygdala and prefrontal cortex—and neurotransmitters--- GABA & serotonin. Despite anxiety being classified less than 50 years ago, researchers & psychologists have developed successful & effective treatments—therapeutically & pharmacologically—- to address this condition & help change the lives of those who are affected. 

        Author’s Bio

        Pranavi Yedluri is a Psychology major at UTD & has a strong interest in the science behind mental health conditions.