Understanding The Depression Neurotransmitters Working Inside Your Brain

Reviewed by Heather Cashell, LCSW

Published 07/14/2022

Humans have studied the brain for thousands of years, and while we’ve learned so much about how it works, there’s still so much left to understand. Since the brain controls nearly everything we do, it’s only right that we look to the brain when our bodies feel out-of-whack.

Things are no different when talking about depression. With what we know today, the symptoms of depression are heavily linked to deficiencies in the brain and other parts of the body. In terms of brain activity, the deficiencies are generally linked to neurotransmitters in the brain.

These neurotransmitters are the real ‘bread and butter’ when it comes to an understanding of how the brain works, how it communicates with itself, and how it communicates with the rest of the body. A deeper understanding of neurotransmitters is essential when understanding the brain.

So, what is a neurotransmitter? And Depression Neurotransmitters? And Depression Neurotransmitters?

Neurotransmitters are the chemical messengers inside the brain that allow neurons to communicate with one another. This communication is one reason we feel pleasure, pain, confusion, a loss of memory, a loss of motor skills, and so much more.

There are really three things in play here -- the neuron, the neurotransmitter, and the synapse. The neuron, also known as the nerve cell, is what the chemicals use as a transport system from one end of a neuron to the other end of the neuron, and eventually to an entirely different neuron.

There are nearly 90 billion neurons located inside the brain, and they’re all important to the brain's function. The neurons are connected to one another through synapses, which are the spaces in-between each neuron.

The neurotransmitter (chemical) travels through the neuron until it arrives at the axon, which is the end of the neuron with the synapse. As the neurotransmitter is released through the synapse, binding receptors are located on the dendrite, the neuron's end with the receptors.

Of course, there is a wide range of things that can go wrong. Since we don’t live in a perfect world, we need to understand how things can go wrong and how it might affect the individual experiencing the imbalance.

Depression Neurotransmitters

Since over 100 different neurotransmitters are found in the brain, they each have their own binding receptors responsible for taking up the neurotransmitters. For example, adrenaline is a neurotransmitter (that also acts as a hormone) with adrenaline receptors.

Unfortunately, many people either have an excess supply of neurotransmitters, a deficient supply of neurotransmitters, an excess of enzymes that break down neurotransmitters, or even a deficient supply of binding receptors.

Any of these situations could affect how we think, behave, act, speak, move, and much more. That’s where we start to see the link between depression and neurotransmitters.

Although most of the neurotransmitters found in the brain can have an indirect effect on depression, three neurotransmitters are receiving the most attention -- dopamine, serotonin, and norepinephrine. Don’t worry, we’ll discuss them in more detail below!

1.    Dopamine And Depression Neurotransmitter

Dopamine is a neurotransmitter in the brain that many people refer to as the ‘pleasure neurotransmitter.’ It’s produced in the body when L-Tyrosine (amino acid) is converted into L-DOPA, the precursor to dopamine. Dopamine also acts as a hormone in the blood.

In the brain, dopamine is responsible for that sense of accomplishment we get when we achieve something and the motivation that keeps us going. It’s not only linked to pleasure but to reward and reinforcement -- such as that feeling we get when someone complements our outfit.

Most people living with depression are also experiencing low dopamine levels, especially when serotonin-related antidepressants aren’t working (also known as selective serotonin reuptake inhibitors or SSRIs). That’s why dopamine medication is often used in addition to serotonin medication.

2.    Serotonin And Depression Neurotransmitter

Serotonin is a neurotransmitter often confused with dopamine. It’s commonly referred to as the ‘happy neurotransmitter’ and is produced in the body when L-Tryptophan is converted into L-5OH-tryptophan, the precursor to serotonin. It also acts as a hormone in the blood.

In terms of depression, serotonin is the most-studied neurotransmitter in the brain. Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed antidepressant in the United States and often help reduce the symptoms of depression.

Several issues can occur with serotonin levels inside the brain. Depression symptoms can occur when not enough serotonin is produced, a lack of binding receptors to receive the serotonin, inability of serotonin to reach serotonin receptors, and even a deficient supply of tryptophan -- since it’s needed to produce serotonin.

3.    Norepinephrine And Depression Neurotransmitter

Norepinephrine is a neurotransmitter often referred to as noradrenaline. It plays a major role in the body’s fight-or-flight response and affects everything from memory to attention, stress, energy, and emotional regulation.

In fact, norepinephrine was once believed to be the primary neurotransmitter involved in a depression instead of serotonin. It was also believed that an increase in norepinephrine caused mania. While certain studies do prove these hypotheses, it doesn’t seem to occur with everyone.

That’s why many people believe norepinephrine is certainly part of the problem, but it isn’t the entire problem. As a result, you often see serotonin-norepinephrine reuptake inhibitors (SNRIs) prescribed instead of SSRIs; that way, the imbalance of norepinephrine is satisfied as well.

4.    Other Depression Neurotransmitters To Consider

There are over 100 neurotransmitters in the brain, and while the three listed above are the main ones involved in depression, there are certainly others worth considering. The three we’re going to add to this list are glutamate, GABA, and acetylcholine.

Acetylcholine is one of the major neurotransmitters linked to memory, attention, focus, and more. Choline is the main precursor to acetylcholine, and it’s largely linked to Alzheimer’s and fibromyalgia.

Glutamate is also involved in learning and memory, but it’s involved in every excitatory brain function. On the other hand, GABA is largely linked to sleep, stress, anxiety, and other mood-related symptoms. Any deficiency could lead to depression-like symptoms.

While GABA is the most intriguing, researchers are still trying to see whether acetylcholine and glutamate have any direct effects on depression.

What Causes Depression Neurotransmitters To Drop?

When talking about depression, most patients experience a decrease in either one, multiple, or all of the neurotransmitters listed above -- especially dopamine, serotonin, and norepinephrine. The decrease is attributed to several factors, and it’s different in each individual.

Let’s take a look at the most common factors that lead to a decrease in neurotransmitters in the brain:

  • A lack of neurotransmitter production inside the brain. For example, the brain isn’t producing enough serotonin.
  • An inefficient supply of precursors to the specific neurotransmitter. For example, not enough tryptophan to convert to serotonin or enough tyrosine to convert to dopamine.
  • An issue with the presynaptic cell causes the neurotransmitter to be taken away before binding to a receptor.
  • An inefficient supply of binding receptor sites would mean there’s no home for the neurotransmitter once released into the synapse.
  • A lack of specific enzymes responsible for helping convert the precursor into the neurotransmitter. This usually means there’s enough of the precursor but not enough enzymes to synthesize the neurotransmitter.

When any of the above three situations occur, there’s a chance you experience a change in behavior due to the lack of neurotransmitter activity in the brain. The longer this problem persists, the higher chance it will affect the rest of the body’s processes.

Finding The Help You Need

Depression is one of the most common mental disorders experienced in the United States today and is often met with various other illnesses, disorders, and behavioral issues. That’s why it’s so important to find the help you need immediately to ensure the problem doesn’t persist or worsen.

That’s where a therapist or psychologist comes in handy. They know how to properly diagnose you with depression and how to treat your type of depression. Since treatment is different in each individual, they take the time to understand your symptoms, current lifestyle, and past experiences.

Of course, you need to understand a problem before you can start to seek the help needed. That’s where Mind Diagnostics comes in to save the day. We’ve created a comprehensive, online depression test to see whether or not you might be experiencing depression.

The test is designed to warn the patient to seek help early on in the process. Don’t worry, we won’t forget about you once you’ve completed the test. Instead, we’ll stick around to ensure you’re matched with the right therapist and ensure you receive the type of care you need.

Together, we can start to build a brighter future for you and your loved ones. Since depression affects more than just the patient, it’s important to take these moments in life seriously. The sooner you receive the help you need, the sooner you can return to the quality life you always imagined for yourself.