Understanding Why Your Brain Does What It Does When You Struggle with Anxiety and Depression

By Carissa Weber, MA, LPC, CSAC

This (first) post from That Darn Amygdala was published on March 27, 2021. To help provide you with the most up-to-date information, this post has been updated. Enjoy!

The statistic still shocks me: “1 out of 4 adults struggle with at least one mental health disorder at any given time.”  At least this is what John Hopkins Hospital said in 2019 before the world was beset with a massive pandemic, financial crisis, and polarized political climate. Honestly, I think these numbers do not truly reflect what is really happening as so many minimize what their mental health is doing. 

There are many factors to our mental health, including:

• genetic
• environmental
• physical health
• substance use
• trauma history
• how we were raised

The list can go on. Today, I want us to focus a bit on the biology side of it. 

Let’s talk about our brain. As many people know, our brain is broken up into many different sections.  As far as mental health goes, I want us to focus on three specific sections: the limbic system, the prefrontal cortex, and neurotransmitters.

The Limbic System

The limbic system, better known as the primitive brain, has been part of us since we were cavemen. This is the part of our brain that protects us. From storing memories, to fleeing bad situations, even to standing up to that aunt who always pinches our cheeks (although we are in our 30s), the limbic system makes sure we survive.  The limbic system is made up of four main parts: that darn amygdala, the thalamus, hypothalamus, and the hippocampus. Let’s explore each one a bit further. 

“1 out of 4 adults struggle with at least one mental health disorder at any given time.” 

John hopkins Hospital

The amygdala. That darn, impulsive, crazy amygdala. This crazy little gland is in the center of our brain and is about the size of a walnut. I like to call our amygdala our “go system.”  Our amygdala responds very impulsively, often without considering consequences.

This is great if you’re being chased by saber tooth cats, running to your car in the rain, or grabbing the candy bar when you are checking out in the gas station. It is the job of the amygdala to make sure our basic needs are being met while staying safe. 

Sometimes, this means that darn amygdala acts super-fast without looking at all the facts of the situation. For example, have you ever gotten nervous before phone call? That is our darn amygdala getting ready to protect us since it doesn’t know what will happen on the call, even if we are just calling to order pizza. Who would’ve thought that this little gland responsible for so much? 

The thalamus is the highway of the limbic system.  It is responsible for taking the information the amygdala collects and dispersing it throughout the brain.  It is kind of like a gatekeeper, allowing certain information in to streamline the reaction that is needed for the situation it is facing. Sometimes it takes in all the information and sometimes it only allows certain information (in the case of mental health, just the negative information that makes us feel worse) to be processed and distributed throughout the brain. This is where our emotions and physical sensations relate to the memories our brain is keeping.  

This hypothalamus serves an important part of the limbic system. This part of our brain is responsible for creating short term memories and maintaining long-term memories. Essentially, the hypothalamus is the key to regulating our reactions, both in emotional and physical in nature.

We cannot forget about our hippocampus.  It works with our amygdala to help create short-term memories and store long-term memories.  What is interesting about the hippocampus, is that it helps release chemical messengers, (known as neurotransmitters) once the amygdala identifies what kind of reaction is needed. 

Science has shown that people who undergo chronic stress and depression have a smaller hippocampus. This is evidence that our brain can be physically changed by our mental health.  Although that is sad news, what is amazing is that our hippocampus can heal if we can maintain healthy stress levels.  There is hope! 

The Prefrontal Cortex

Now that we’ve talked about the basics of the limbic system, let’s talk a bit about our prefrontal cortex. Our prefrontal cortex is part of our brain located directly behind our forehead. This is something that has developed over thousands of years, and I like to call it our “stop system.” The prefrontal cortex likes to plan things and take all facts into consideration. It enjoys slowing down and solving problems versus reacting to them like the amygdala.

The prefrontal cortex developed much later in our history than the limbic system as an additional way to keep us safe. For example, it is the part of our brain that says, “I’m really hungry, but I don’t need the consequences of eating poisonous berries, or that expired sushi on the fridge shelf.”  It takes a few minutes for the prefrontal cortex to kick in, but it is typically able to communicate with the amygdala to calm it down. All of this communication happens via neurotransmitters. 

An important part of our prefrontal cortex is the insula. Located in the middle of the prefrontal cortex, the insula is responsible for processing all of our sensory information (you know, like what we are seeing, tasting, and smelling). Although located in the prefrontal cortex, the insula has direct links to:

• That darn amygdala
• The thalamus
• The hypothalamus
• The hippocampus

This means it can get important environmental information (for example, the smell of smoke and sight of flames) to the limbic system to help keep us alive!

What are Neurotransmitters?

Neurotransmitters are chemicals in our brain that signal us to behave in a certain way. The neurotransmitters associated with mental health include (but not limited to) dopamine, serotonin, norepinephrine, acetylcholine, GABA, glutamate, and endorphins. It is important to know that this is how our brain communicates when we are experiencing some sort of emotion, positive or negative, by how much (or how little) of a certain neurotransmitter is present in our brain. 

There is a lot more to mental health than “just emotions.” Thank you for taking time to learn about the major players involved in your mental health. It is my hope this post helps you be less afraid of mental health, and more empowered to conquer it!   

To recap today’s blog post: 
– the brain is most definitely involved in mental health 
– there are parts of our brain that control how we react to situations 
– we can change how our brain works by using coping skills to make those changes 
– Neurotransmitters are how our brain talks its different parts 

Bonus Material

Image Sources

• Carissa Weber at www.thatdarnamygdala.com
• www.pexels.com