How Do You “Get” Depression? Where Depression Starts

Many people think that depression has one specific and obvious cause, or that its symptoms are limited to sadness. However, it's not so simple. There is not a singular cause for depression, but many causes. As we learn more about the condition, we are developing better ways to treat and prevent it.  

What is depression?

Depression is characterized by a series of symptoms including:

• Persistent feelings of sadness or hopelessness
• Loss of interest in activities or hobbies
• Lack of motivation
• Decreased energy
• Trouble sleeping/fatigue
• Difficulty concentrating or making decisions
• Unexplained physical pain
• Weight changes
• Irritability
• Excessive guilt and low self-esteem
• Suicidal thoughts

Although depression is very treatable, many people suffer in silence. Part of what makes depression so hard to deal with is that it changes how we think about ourselves, how we feel about our ability to cope with life, and can make us believe that there is no end in sight. 

If you are experiencing suicidal thoughts or urges, call the National Suicide Prevention Lifeline at 988. Support is available 24/7. If you are experiencing trauma, support is available. Please see our Get Help Now page for more resources.

Where exactly does depression come from?

Depression is a complicated disorder. The medical community is still in the early stages of grasping it. So far, researchers have found that it is unlikely that there is a single cause for depression for everyone. We also know that it is not contagious and doesn't spread between people.

You may have heard that depression comes from a combination of genetics and environment. While this is true, it's only part of the picture. In fact, the disorder can be linked to several factors. What triggers depression in one person may or may not be the same trigger for someone else. The brain, genetics, stress, and physical health all seem to play a role.

Brain

We often hear that depression stems from a chemical imbalance. Words like "dopamine" and "serotonin" may even come to mind. While these important neurotransmitters can play a part in certain symptoms, the role of the brain is far more complex.

Recent brain imaging studies have found some surprising results. For example, a region of the brain called the hippocampus, the area responsible for memory, is smaller in those who are diagnosed with depression and bipolar disorder. There are many theories about why this may be the case. Some suggest those born with a small hippocampus are just more likely to experience depression. Others think the effect of a hormone called cortisol is responsible. Research in women has shown that the organ is even smaller in those who have multiple episodes of depression. Scientists believe there is valuable information to be learned about this relationship.

Researchers are also exploring the link between low moods and lower production of nerve cells in the hippocampus. They believe that stress slows the production of nerve cells (resulting in the smaller hippocampus). Nerve cells are needed to receive important neurotransmitters like dopamine and serotonin. Without the right number of receptors, it doesn't matter how much of the neurotransmitters the brain produces.

This is changing the way the medical community thinks about medications like antidepressants. It appears that medication may allow new nerve cells to grow rather than flooding the body with the right neurotransmitters. This process can take a few weeks, which may explain the delay between starting an antidepressant and feeling better. As we learn more about how antidepressants affect nerve cell growth, we can potentially develop medications that work faster.

We also know that other areas of the brain are affected by mood. The amygdala, for example, the region of the brain associated with our emotions, is more active when someone is experiencing depression. Other neurotransmitters such as norepinephrine and acetylcholine, which are linked to motivation and learning, may also play a part in the condition. As researchers continue mapping the brain, we will likely learn more about where depression comes from (in a biological sense) and create better treatment methods.

Genetics

Everyone is born with a unique set of genes that come from our parents. These genes make proteins that tell our bodies to start or stop certain biological processes. Because some genes are linked to mood, we may be born with genes that make us more or less likely to experience certain disorders like depression.

For those who are more genetically predisposed to depression, all hope is not lost. There are many other influences such as lifestyle choices and physical health that can lower the chances of experiencing the condition.

As scientists understand more about the function of each gene, they are learning more about the specific origins of depression. This information is shaping prevention methods and treatments for the condition. In fact, genetically driven treatment options are already available. Genetic testing for medications may help patients find the right antidepressant for their biology through a simple oral swab.

Stress

Sometimes, depression surfaces as a result of the situations we experience. These situations can range from tragic events like the loss of a loved one or job to chronic stressors, like low-income. Stress plays a major role in the development of depression. When we are depressed, levels of a hormone called CRH increase.

Our hypothalamus secretes CRH when we are stressed, which then goes on to promote the release of cortisol in the body (further increasing stress symptoms). We can lower our levels of CRH with antidepressants and electroconvulsive therapy. Other treatment options like talk therapy and lifestyle changes can also help manage stress.

Trauma

There appears to be a strong relationship between trauma and depression. Examples of traumatic events include (but are not limited to):

• Death of a loved one
• Separation or withdrawal of affection from a loved one
• Sexual abuse
• Physical abuse
• Emotional abuse
• Serious accidents/illness
• Witnessing violence
• Natural disasters

Not everyone who experiences a traumatic event will develop depression. However, many researchers believe that those who experience trauma, especially early in life, undergo chemical or cellular changes in the brain. Scientists are trying to better understand the link between trauma and depression, but some treatment methods, like talk therapy, show promising results for both depression and trauma recovery.

Medical

Sometimes, depression is a symptom of another health condition. Certain chronic illnesses such as diabetes, heart disease, multiple sclerosis, and hypothyroidism can cause depression. Some vitamin deficiencies may be to blame too. If depression is suspected, it is important for your doctor to perform routine blood work and a physical exam to rule out other underlying health conditions.

Medications taken for other health problems may also cause depression. Some popular acne medications, antivirals, and corticosteroids are associated with the condition. A doctor should closely evaluate all prescriptions before diagnosing depression. Getting relief may be as simple as switching pills.

Another medical factor that contributes to depression is overall health. Diet, exercise, and lifestyle habits (like smoking or drinking) are linked to the condition. Doctors often recommend lifestyle changes to treat depression while taking medication. Many symptoms can be managed through nutritious meals, frequent exercise, healthy sleep cycles, and the avoidance of habit-forming substances.

Does having depression mean that something is wrong with you?

 Just because someone has depression, it doesn't mean that anything is "wrong" with them. Depression stems from many origins. Even though some of these factors, like genetics or underlying medical diagnoses, can't be immediately cured or changed, the symptoms of depression are still very treatable.

What's next?

Although we are in the early learning stages of depression, there are many effective treatment approaches. Consider the following:

• Antidepressants: Antidepressants can help tackle the biological factors contributing to depression. By working with your individual brain and body chemistry, you can help stabilize neurotransmitter levels, grow nerve cells, and lower CHR levels.
• Talk Therapy: Talk therapy can help lower stress levels, process trauma, or assist in developing healthy habits that can manage symptoms. Therapy, particularly cognitive-behavioral therapy, has long been shown to be an effective treatment option for depression. With online therapists, like those available through BetterHelp, treatment is just a quick click away. Online therapy is not only more convenient than traditional therapy, but it can also be more affordable. 
• Lifestyle Changes: Diet, exercise, and sleep are the foundation of depression symptom management. Talk with a doctor to rule out underlying factors first, then consider making positive lifestyle changes to aid in your treatment.