Depression is a common but serious mental health condition that can cause a number of disruptive mental health symptoms. Diagnosing this disorder focuses on identifying challenges in mood, thinking, and behavior. However, physical, chemical, and electrical effects within the brain are thought to be the root cause of many of these symptoms.

Turning to evidence-based treatment can help put your brain on the path to healing. Before you get to that point, though, it’s helpful to learn more about the brain during depression and the changes that contribute to nearly every symptom you experience.

Understanding the Roles and Functions of the Brain

To understand what happens to the brain during depression, you should know the basic functions of the brain and how they affect your mood, thoughts, and behavior. The human brain is an overwhelmingly complex structure. While humans have learned a lot about its functions and anatomy, there’s much that we still don’t understand.

Below is a brief overview of the most important findings from neuroscience related to mood, cognition, and depression. While this primer is no doubt an oversimplification, it can help you understand the basics of what happens to the brain during depression:

Brain Structures

The brain is broken into three main structures:

  • Forebrain
  • Midbrain
  • Hindbrain

The midbrain and hindbrain are largely responsible for controlling automatic and life-preserving functions. They also serve to relay sensory information to other areas of the brain.

The forebrain is the largest part of the brain structure. It contains the wrinkly and folded tissue called the cerebrum that gives the brain its distinct appearance. The forebrain plays the largest role in mood and cognition, and it is further divided into several lobes, each with distinct functions:

  • Frontal Lobes: Located at the front of the brain behind the forehead and are responsible for reasoned thought, executive control, personality, and social skills
  • Parietal Lobes: Located in the middle section of the brain and house language skills, speech skills, and several sensory functions
  • Occipital Lobes: Positioned at the back of the brain and are largely dedicated to vision and images
  • Temporal Lobes: Positioned on the sides of the brain and are responsible for forming memories and auditory processing

The last important brain structure to consider is the inner brain, which comprises the thalamus, hypothalamus, and hippocampus. These are your brain’s emotional and motivational centers. They produce many of the essential chemicals that are responsible for brain functioning.

Electrical Pathways

The brain is made up of around 100 billion brain cells called neurons. Neurons are the basic processing unit of the brain, and the neurons communicate with one another through a combination of electrical and chemical activity.

Your brain’s neurons are linked with each other in complex pathways that stretch throughout your entire body. In combination, your neuron pathways make up what is commonly referred to as the nervous system.

Essentially, when a neuron needs to communicate with another part of the brain — such as to communicate a thought, trigger an action, or feel an emotion — it creates a brief electrical impulse. This impulse then causes a chain reaction of neurons sending electrical signals to each other.

Pathways that get used frequently tend to form stronger connections with one another. By analogy, consider a path through a park or wooded area. The more people who walk on the path, the wider and more road-like it becomes.

When people stop using the pathway, however, vegetation starts to creep back over the path. Ultimately, a lack of use could cause it to fade away entirely. Neural pathways work in a similar way.

Neurochemical Interactions

Electricity isn’t the only way brain cells communicate. When a neuron is triggered by an electrical impulse, it releases chemicals known as neurotransmitters to the next neuron in the chain. The electricity is just the ignition switch, while neurotransmitters contain the message itself.

Neuroscientists estimate that there are well over 100 different neurotransmitters in the brain. But for the purposes of understanding the effects on the brain during depression, there are just a few key neurotransmitters that have been identified as highly important.

Dopamine

Dopamine is the brain’s primary reward neurotransmitter. It is critical for motivation and learning. When neurons release dopamine, they generally signal that an experience was positive and should be repeated.

Serotonin

Serotonin has multiple roles in the brain. One of the key effects of serotonin is in regulating mood and sleep. When serotonin levels are too high or too low, people can experience several emotional symptoms, such as stress, anger, or sadness.

Norepinephrine

Norepinephrine, also known as adrenaline, is both a hormone and a neurotransmitter. It is largely responsible for attention, focus, energy, and stress responses. It plays an important role in the body’s fight-or-flight response and may contribute to feelings of anxiety, stress, and fear.

Effects on the Brain During Depression

Each of the functions and structures outlined above undergoes substantial changes during depression. These changes are directly linked to the mental health symptoms you experience, and recovery from depression is associated with the reversal of these brain changes themselves.

Neurochemical Imbalances

First, the brain during depression has been shown to have neurochemical imbalances. Specifically, levels of dopamine, serotonin, and norepinephrine are all reduced significantly in people who are experiencing depression. This reduction in key neurotransmitters has a number of downstream effects.

For instance, the reduction of dopamine makes it harder for people to find the motivation to go about their daily lives. It also contributes to a loss of interest in hobbies or activities.

When you are lacking in dopamine, nearly every aspect of your life can seem drab and uninteresting when compared to how you used to feel. As a result, you might find it difficult to change your behavioral patterns in ways that can help ameliorate depressive symptoms.

Depletion of serotonin levels can contribute substantially to your experience of chronically depressed mood, guilt, irritability, or a feeling of hopelessness. It can lead to the common experience of sleep challenges experienced by people with depressive disorders as well. You might start to sleep too much or too little.

Finally, reductions in norepinephrine mean that people living with depression often feel chronic fatigue and have trouble focusing. Every day can feel like you have extremely limited energy reserves, even if you haven’t done any particularly demanding tasks.

Reduced Electrical Activity

A depressed brain shows much lower signs of activity in several key regions, according to fMRI and PET scans of people who are experiencing the condition. These types of scans don’t measure electrical activity directly. Instead, they assess overall brain activity levels by measuring metabolism and blood flow.

Reduced activity means that brain regions are working less, meaning neurons are not firing at what is considered to be a “normal” rate. Essentially, people living with depression are experiencing significantly reduced brain functioning in several key regions, including the following:

  • Prefrontal Cortex: Part of the frontal lobes that plays a major role in decision-making and executive functioning
  • Hippocampus: Structure within the midbrain that’s responsible for memory and learning
  • Anterior Cingulate Cortex: Part of the frontal lobes that influences emotions, reward anticipation, impulse control, and attention

When these areas aren’t functioning at their full capacity, it can make it extremely difficult for people to think clearly, control their emotional state, or build the motivation necessary to seek out rewarding activities.

Shrinking of Brain Regions

Living with the reduced electrical activity described above for long periods will ultimately lead to a shrinking of these key brain regions. Scientists have found that the prefrontal cortex, hippocampus, and anterior cingulate cortex — as well as several other critical brain structures — will all start to shrink in people living with depression for long periods.

These changes make one thing clear: depression is not simply a matter of willpower or personal character. Living with depression causes substantial changes in the very structure of the brain.

These alterations make it difficult for people to go about their daily lives as they see fit. Many people living with a depressive disorder will need professional treatment to overcome or manage it.

Can Your Brain Recover?

The good news is that the brain changes experienced during depression are often completely reversible. Your brain has an astounding ability to heal itself and create new connections, a phenomenon that neuroscientists have labeled as neuroplasticity.

But to achieve this healing, it’s critical that people experiencing severe depression start receiving the support of a team of mental health professionals. Evidence-based depression treatment is the fastest path to a full recovery.

Getting professional help can even accelerate the process of brain healing for people taking the first steps toward breaking free from depression. Below are a few of the best treatment options for depression.

Psychiatry and Medication Management

Psychiatric medication focuses on the neurochemical changes experienced by people living with depression. Targeted medication options can increase your brain’s production of serotonin, dopamine, or norepinephrine, bringing it back in line with neurotypical controls.

Medication management is the process of helping people find the medication that works best for them. Rather than simply giving you a prescription, medication management works closely with you over the course of weeks or months.

Your mental health care team will ensure that your medication is working as intended and that you’re seeing positive benefits. Medication management also allows you to make changes throughout the process so that you can get the results you want.

Deep Transcranial Magnetic Stimulation

Deep transcranial magnetic stimulation (dTMS) focuses on electrical activity in the brain. Using advanced neurotechnologies, dTMS provides targeted electrical stimulation to regions deep within the brain. In turn, this creates lasting improvements in overall brain functioning. dTMS is an FDA-approved treatment option for severe depression.

This method uses specialized caps equipped with magnets to create the electrical impulses. It is a completely non-invasive process. Several treatment sessions can make dramatic improvements in your depression symptoms that last for years to come.

Talk Therapy

Talk therapy approaches focus on helping people build healthier coping skills, thought patterns, and behavioral strategies known to be effective in combating depression. While this isn’t a direct brain approach, it can spark lasting brain healing and repair when you apply these skills in everyday life.

There are several scientifically supported talk therapy options that can help people achieve a lasting recovery from depression. Starting in-person or virtual talk therapy can get you connected with a trusted therapist to start your path to healing.

Start Treatment With Plus by APN

Plus by APN is dedicated to providing our clients with the best in cutting-edge and traditional depression treatment options. If you’ve been living with depression but are ready to take the first steps toward recovery, we want to help.

Reach out to our team by calling 424.644.6486, filling out our confidential online form, or using our live chat function to hear more about the number of depression treatment options we have available. Don’t wait — start getting professional mental health support today.

References

  • “Brain Basics: Know Your Brain.” National Institute of Neurological Disorders and Stroke, www.ninds.nih.gov/health-information/public-education/brain-basics/brain-basics-know-your-brain. Accessed 6 Sept. 2024.
  • Hasler, Gregor. “Pathophysiology of depression: do we have any solid evidence of interest to clinicians?.” World psychiatry : official journal of the World Psychiatric Association (WPA) vol. 9,3 (2010): 155-61. doi:10.1002/j.2051-5545.2010.tb00298.x
  • Zhang, Fei-Fei et al. “Brain structure alterations in depression: Psychoradiological evidence.” CNS neuroscience & therapeutics vol. 24,11 (2018): 994-1003. doi:10.1111/cns.12835