Depression is a mystery. Like many other mental illnesses, we don’t know exactly what causes depression, why some people develop it and others don’t, or why certain treatments work for one person but not another. According to the World Health Organization, approximately 280 million people in the world suffer from depression, and yet it continues to mystify neurologists, psychologists, and geneticists all over the world. We are aware of certain factors that increase a person’s chance of developing depression, but we need to know more in order to improve the available treatments. At the same time, so much more is known about depression today than just a decade ago. Even though we don’t know exactly what causes it, we do have some information about how depression affects the brain.
How depression works in the brain
People who don’t realize they’re suffering from depression often shame themselves for not “snapping out of it.” They may receive similar messages from friends, family or work colleagues, suggesting that if they would just put in more effort or “try” to enjoy themselves, they would do better or feel better. But what most people don’t understand is that these messages are like telling a person to try harder to get over their diabetes. Depression is an illness of the brain. It is not something a person can think themselves out of. Even though we don’t know exactly what causes depression, we do know it’s a real illness, and we understand a little bit about how it works in the brain. Here are three ways depression affects the brain.
#1. Depression is associated with areas of brain shrinkage
The onset of depressive episodes is often linked to high levels of stress. Whether this stress is long-term or recurrent, the high levels of stress hormones can result in a reduction in the size of the nerve cells and the number of connections in certain parts of the brain. The longer your depression goes untreated, the more likely certain parts of your brain will shrink.The areas affected include:
Hippocampus – responsible for controlling memory and emotion
Cortex – responsible for thinking and cognition
These brain changes result in the cognitive symptoms of depression, including forgetfulness, confusion, and difficulty concentrating.
#2. Depression is also associated with larger or overactive areas of the brain
Just as some parts of the brain are smaller and less active in those who suffer from depression, other parts are larger or more active. These include:
Hypothalamus – responsible for stress response coordination
Amygdala – responsible for processing fear and threatening stimuli
These brain changes result in an attunement to negative stimuli and an increase in negative emotions.
#3. Depression is linked to the impairment of the reward circuit
The human brain is a complex structure containing billions of neurons communicating through electrical signals. These signals are moved from one neuron to another by way of chemicals called neurotransmitters. Depression disrupts this system of communication. Depression is also exacerbated by this disruption. For example, an overactive amygdala stimulates the secretion of stress hormones. An excessive amount of stress hormones impairs the strength of neurotransmitters, which disrupts important components of the brain’s reward circuit. An impaired reward circuit results in a reduced response to positive stimuli, meaning the individual is unable to experience pleasure from once-enjoyable activities. At the same time, the overactive amygdala keeps the individual attuned to negative stimuli and further generates negative emotions, resulting in an unhealthy cycle that’s both emotional and physiological.
Why this matters
Although knowing the biomechanisms of depression in the brain won’t directly change an individual’s ability to manage their symptoms, it can help them understand what’s happening to them. The information can also help lead to more effective treatments for depression. Over the last half-century, depression medication has evolved right alongside our deepening knowledge of how depression works in the brain. Many people are able to find relief from their symptoms with modern antidepressants. But because current antidepressant medications work only for some of the people and only some of the time, scientists continue to search for and develop more effective treatments. The therapeutic use of ketamine and psychedelics, for example, are showing promise for people with treatment of depression (characterized by a failure to respond to two or more depression medications). While these particular hallucinogenic drugs may not become common treatments for depression, the biomechanics of their effectiveness can help us learn more about what is needed to create effective depression treatments for everyone who needs them.
Participate in a research study for major depressive disorder in San Diego
At Synergy Research Centers in San Diego, we’re currently enrolling eligible participants in several depression clinical research studies in Lemon Grove. We begin with a short phone interview, during which we’ll ask questions about your battle with major depression, as well as more practical information about your travel accommodations, age, and medical history. Once we’ve determined your eligibility, we’ll invite you to come in to our facility in Lemon Grove and begin the study. During the depression trial, you will either be given a new depression treatment or a placebo. You’ll then communicate how you are feeling with our research team, and we’ll carefully monitor you every step of the way. Some of our depression studies also offer financial compensation for participation. For more information on our depression clinical study or any of our other clinical trials, give us a call at (888) 539-0282 or fill out our contact form today.