For over thirty years, people have been told that the cause of depression is a chemical imbalance in the brain, specifically an imbalance of serotonin.  If you suffer from depression, it is probably what you have been told and you were prescribed antidepressants such as selective serotonin reuptake inhibitors (SSRIs).  But a bombshell new study shows that there is no clear evidence that serotonin levels are the cause of depression. 

Cause of Depression: Chemical Imbalance Theory

In the 1960’s, the theory was proposed that the cause of depression is an imbalance of serotonin in the brain.  This theory was widely promoted by the pharmaceutical industry in marketing antidepressants known as SSRIs (Serotonin Reuptake Inhibitors).  The American Psychiatric Association endorsed the theory saying that the differences in certain chemicals in the brain may contribute to depression.  Doctors and psychiatrists repeated the message and people accepted it. 

Even though the chemical imbalance theory has been widely accepted, there has never been a comprehensive study supporting the idea that depression is the result of low serotonin.  In fact, drug trials show little difference between antidepressants and a placebo in treating depression.  Then why did the medical community embrace the serotonin theory?  Because they found that antidepressants do increase brain levels of serotonin, therefore, they hypothesized that depression must be caused by low levels of serotonin.  They did studies, but the findings were unreliable, so they ignored the findings they didn’t like and published the ones they did like. 

Cause Of Depression: The Bombshell Review Study

On July 20,2022 (two weeks ago), a review study was published in Molecular Psychiatry by researchers from University College London.  It is titled, “The Serotonin Theory Of Depression: A Systematic Umbrella Review Of The Evidence.” All of the past studies and analyses of the relationship of serotonin on depression that included tens of thousands of participants were exhaustively reviewed and analyzed with the conclusion that there is no clear evidence that serotonin levels or serotonin activity are responsible as the cause of depression. 

Professor Joanna Moncrief, the lead author of the study, said, “It is always difficult to prove a negative, but I think we can safely say that after a vast amount of research conducted over several decades, there is no convincing evidence that depression is caused by serotonin abnormalities, particularly by lower levels or reduced activity of serotonin…Many people take antidepressants because they have been led to believe their depression has a biochemical cause, but this new research suggests this belief is not grounded in evidence.” 

Then What Is The Cause Of Depression?

If you suffer from depression, this should come as good news.  Research shows that people who believe that the cause of their depression is a biological disorder such as a chemical imbalance in their brain, are more pessimistic about their chances for recovery.  In other words, if you’re told that your depression is something biological that won’t change and you’ll have to be dependent on drugs to alter your brain’s chemistry, that means that you will never get over it and be normal again.  But if, as the new study says, depression is not caused by your brain chemistry and antidepressants are little more than placebos, then there is hope that recovery is possible.  

Mitch Prinstein, the American Psychological Association’s chief science officer, responded to the study by saying that there are two facts about depression that this study makes clear: 

Depression is a heterogenous disorder. 

In other words, it isn’t caused by just one thing such as a chemical imbalance or absence of serotonin.  Depression has many causes and presents differently from person to person.  It’s not like a virus that is the same from person to person.  Depression is diverse. 

There is no single treatment for everyone with depression.

There is no “magic bullet” drug that will fix every case of depression.  And antidepressant drugs have actually been found to be questionable at this point as to their effectiveness.  It’s uncertain right now whether they do more harm than good.  But talk therapies such as Emotionally Focused Therapy that address non-biological causes have been found to be effective.  The conventional approach to depression has always been drugs plus talk therapy, but it’s looking like the new wisdom will be to prescribe talk therapy, period.  Time will tell. 

Emotionally Focused Therapy And Depression

While it turns out that there is no link between a chemical imbalance in the brain and depression, there is a link between depression and relationship distress.  Depression and relationship distress reinforce one another.  Depression can cause relationship distress, and relationship distress can cause depression.  Emotional separation and disconnection create depression.  When we feel disconnected from a primary relationship, loneliness, low self-worth, despair, hopelessness, and many dark feelings associated with depression emerge. 

Emotionally Focused Therapy is an evidence-based therapy.  There is more research behind EFT than any other therapy model.  And it has been shown that EFT is highly effective in treating depression because EFT uses the power of human connection.  Study after study shows that when we are securely connected to a primary relationship, anxiety and depression are significantly lessened and we become more resilient. 

I am not saying that EFT is the magic bullet any more than a doctor can say that an antidepressant is the magic bullet.  But I am saying that studies have proven over and over that EFT works, while this study blows out of the water the chemical imbalance theory.  Talk therapy no longer takes a back seat to drug therapy.  In fact, talk therapy at this point seems to be the best treatment. 

In closing, let me say that if you are taking antidepressants, don’t stop without speaking to your doctor. But you should take a close look at the new research.  In fact, you can find the study here.  I urge you to read more about depression treatment, and then contact us to schedule a free thirty-minute consultation to learn how Emotionally Focused Therapy can help you with your depression. 

Dr. Bernis Riley, LPC-S, Psy.D., is a certified EFT therapist.  She is the co-founder and Clinical Director of SoulCare Counseling.  Dr. Riley is taking new clients.