Have you ever heard that depression is caused by a chemical imbalance in the brain? Most of us believed this for many years – but it turns out it’s not the whole truth. Depression is a complex disease affecting over 280 million people worldwide, and a chemical imbalance is not what causes it.
Read on to learn more about chemical imbalances in the brain, and why the chemical imbalance theory is a myth.
What is a chemical imbalance in the brain?
A chemical imbalance in the brain is when certain neurotransmitters are higher or lower than they should be.
Neurotransmitters are chemicals that communicate with one another and help your brain and body work together. They bring messages between nerve cells and target cells. Your body can’t work without neurotransmitters.
Some commonly known neurotransmitters are:
- GABA: regulates anxiety, sleep, motivation, and other things
- Histamine: plays a role in asthma and other disorders; regulates wakefulness and motivation
- Serotonin: regulates mood, anxiety, and pain, among other things
- Dopamine: plays a role in the brain’s reward system and regulates pleasure, focus, mood, and other things
- Endorphins: a natural pain reliever that regulates your perception of pain
- Epinephrine and norepinephrine: responsible for your body’s stress response (“Fight, flight, or freeze response”)
Every neurotransmitter plays a critical role in your body. But sometimes, they get unbalanced, which is what we refer to when we talk about a chemical imbalance in the brain.
What can cause a chemical imbalance in the brain?
There is no clear, evidence-based cause for a chemical imbalance in the brain. Some people do seem to have less (or more) of certain neurotransmitters than others, but experts still don’t know what causes this imbalance in some people but not in others.
Many different factors have been linked to neurotransmitters not working as they should. Some of these possible factors include:
- Sensitivity of receptors; sometimes, receptors are over- or under-sensitive to certain neurotransmitters which can change how they respond to these neurotransmitters
- The origin cell may release a lower amount of certain neurotransmitters
- Cells may “reuptake” or absorb too much of a certain neurotransmitter too quickly, leaving less of it available for use
In addition, there are other factors that could change the levels of chemicals in your brain. For example, some researchers suggest that mitochondrial disease could contribute to a chemical imbalance, and that it could be linked to depression. Mitochondria are a type of organelle that’s found in every cell in our bodies. It has DNA that’s separate from the rest of your body. Some people have mitochondrial diseases which are thought to be caused by mutations in mitochondrial DNA.
Chronic stress can also change the levels of neurotransmitters in your brain. The inflammation that comes along with chronic stress can also have a negative effect on your brain. This is why, especially if you’re already dealing with a mental health condition, it’s critical to learn how to manage your stress levels.
Lastly, drug and alcohol use also has an effect on neurotransmitters. They can both mimic neurotransmitters as well as change the levels of your natural neurotransmitters. This is one of the reasons why people become addicted to drugs and alcohol.
Is depression caused by a chemical imbalance in the brain?
For many years, people – including experts – claimed that depression, and other mental illnesses, was caused by a chemical imbalance in the brain. This is called the “chemical imbalance theory.” In particular, they said that too little serotonin causes depression. This is why many people take antidepressant medication – they may have believed that by fixing this chemical imbalance, their depression would disappear.
Now, with newer research, we know this not to be true. At best, it’s an oversimplification of what depression is and what causes it.
A 2022 systematic review found no clear evidence that serotonin levels contribute to depression at all. The authors of the study wrote that they found “no support for the hypothesis that depression is caused by lowered serotonin activity or concentrations.”
This is why the effectiveness of antidepressant medications is far less than 100% (most studies place the effectiveness of antidepressant medication at between 40 and 60%). If chemical imbalance was the sole cause of depression, then every person with depression should be cured after taking medication that “corrects” the imbalance. As we know, this isn’t the case.
Some studies have found links between depression (and other mental illnesses) and brain chemicals. For example, one study found that the GABA neurotransmitter may play a role in anxiety disorders.
But to say that these chemical imbalances “cause” mental illnesses is an oversimplification of extremely complex conditions.
What really causes depression?
If the chemical imbalance theory is incorrect, then what really causes depression?
Experts say that, in reality, depression is a complex disease with a multitude of causes. Many different factors can contribute to one’s risk of developing depression. But there’s no single factor that will definitively cause depression in every single person who experiences it. These “causes”or risk factors may raise your risk of depression, but many people live with these risk factors and never become depressed.
For example, having a genetic predisposition significantly increases your risk of depression. But not everyone who has a parent with depression develops it themselves.
Some other risk factors for depression include:
- Going through a major life change, like a move or a divorce
- Experiencing traumatic events either currently or in early childhood
- Being a victim of abuse or assault
- Having significant financial problems
- Using alcohol or drugs
- Having medical problems like cancer or chronic pain
- Taking certain medications
- Feeling lonely or isolated
- Hormonal changes that may come along with pregnancy, menstruation, or menopause
Treatment for depression at The Center ● A Place of HOPE
So does this mean that psychiatric medication is ineffective? Absolutely not. Many people find relief from their depression and anxiety through medication, and it can be part of your treatment plan if it works for you.
However, it does mean that, for most people, depression recovery is more complex than just taking medication. You may need to implement other habits, like connecting with friends and eating a healthy diet, to fully recover.
At The Center, we use a unique Whole Person Care approach for depression treatment. This is precisely because we understand deeply how complex depression is – we’ve always known that it’s about a lot more than a chemical imbalance in the brain. That’s why we’ve been named one of the Top 10 Treatment Facilities for Depression in the United States.
What has led to depression for you is different than what’s led to depression for someone else. Your treatment plan with us will always be individualized to you and your needs. We make sure the Whole You is taken care of – including your mental, physical, spiritual, social, and intellectual well-being.
Get in touch with our admissions team for more information about our unique programs and intake process.