The National Institute of Health reports that approximately 21 million adults or 8.4% of all adults in the U.S. had depression in 2020. Of these 21 million adults, an estimated 66% received treatment. For decades, the common theory for the cause of major depression was low serotonin levels or a ‘chemical imbalance.’ A recent study from the University College London (Moncrieff and colleagues, July 2022) reviewed existing research literature and concluded that depression is not caused by low serotonin levels. While these conclusions are based upon the prior research findings of others, this article has become a hot discussion topic on social media and news. The conclusion that serotonin does not cause major depression is relevant because it suggests that SSRI/SNRI antidepressant medications such as Prozac (Fluoxetine), Zoloft (Sertraline), Celexa (Citalopram), Cymbalta (Duloxetine), and Effexor (venlafaxine) may not be the ideal treatment for major depression and depression symptoms. We need clarity on these confusing findings! In this post I will review the University College London research findings, depression treatment best practices, and my clinical practice findings on these topics.
Questioning the Role of Serotonin in Depression
Moncrieff and colleagues published a journal article that challenged the role of the neurotransmitter, serotonin, in causing and maintaining depression. Their article reviewed and summarized findings from 17 previously published research articles (dated 2006-2020). As a clinician, I am not deeply familiar with the research and will summarize what I found. The researchers grouped the studies according to their hypotheses and concluded:
Causes of Major Depression and Best Practices for Treatment
The exact causes and pathways for major depression to start, continue, and reoccur are not entirely clear due to research limitations and the presence of multiple contributing factors. The bio-medical model historically focused the impact of medication on one’s health. Over time, the bio-medical model evolved into the biopsychosocial model, which determined the effects of thoughts, emotions, behaviors, and environment upon mental health. While low serotonin levels and the “chemical imbalance” theories have existed for decades, there is no way to understand the exact neurological process for a depressed individual. As argued by psychiatrist Dr. Rettew here, Moncrieff’s article does not prove that biology/genetics and the brain/nervous system are not involved in the origin and maintenance of depression. While we don’t understand exactly how antidepressants work, we do know that they are helping millions of people feel better.
The current clinical guideline for the treatment of major depression is a combination of psychotherapy (likely cognitive behavioral therapy) and antidepressant medication (prescribed and managed by psychiatrist or general practitioner). Lifestyle practices that support depression management involve improving one’s physical health and wellness, developing and engaging in healthy relationships, and setting and working on personal goals. Many times these lifestyle practices are effortful for the depressed individual. Unfortunately the depressed individual may not feel like doing things and will avoid things that seem effortful. Since these changes can seem overwhelming, it is recommended to consult with a psychologist/therapist and personal physician to get support and treatment before symptoms and functioning worsen.
Dr. Soo Hoo’s Clinical Observations
Most patients with depression first talk about their concerns with their primary care doctor. While this visit may or may not result in the recommendation for therapy, it almost certainly will involve a discussion about medication and possibly a prescription. The prescription may not be what everyone needs, but it’s a reasonable starting point. When working with patients, I explore how and why symptoms started, developed, and continue. There is no “one size fits all” approach to treatment; there is not even a “one medication fits all” or “one therapist fits all.” I am often asked by patients whether I think they should take medication or continue with it (even though I am not a prescriber). As the patient and I discuss this, we consider the potential costs and benefits, the intensity of their symptoms, how their symptoms impact their daily living, and their history with their disorder- in this case, depression.
Reactions and Impact
While Moncrieff’s study conclusions felt to me like getting hit between the eyes, it was helpful to know the state of the research findings. Despite Moncrieff’s conclusions, antidepressants are the best remedy we have for treating some depressions. I am concerned that this research review might discourage people from using a needed and helpful treatment. Aside from feeling bad, depression can affect one’s relationships and quality of life. Patients who suffer from a vegetative depression (stereotypical lack of energy and motivation) may be judged as “lazy” and feel guilty and worthless as a result. The availability of medication treatments that work helps the individual to feel empowered and less stigmatized. Could it be that these findings will lead to an increase in alcohol abuse to “feel better”? On the flip side, these findings might encourage those who are not responding to medication to try new treatments, such as psychotherapy or Transcranial Magnetic Stimulation (TMS).
Are Antidepressants Addictive?
Some patients express concerns about becoming “dependent” upon antidepressants. Your body will have to get adjusted to having an antidepressant in your system. As such, you might experience unpleasant symptoms as you start the medication or if you miss a dose or stop taking it abruptly. However, in comparison to controlled substances, there are no cravings, “euphoric rush”, or giving up daily responsibilities to obtain the antidepressant. Depressed individuals with histories of addiction are also able to take antidepressants.
Reasons to Consider Antidepressants
I have worked with depressed patients that had great responses to medication treatment. I have also seen middle-aged to older adults with long histories of depression thrive on these as “routine medications.” If a patient decides to take an antidepressant medication, it needs to be started, continued/adjusted, and ended with the guidance of the prescriber. Changing the dosing or not taking it as prescribed (such as skipping doses or drinking alcohol) can impact your response. If you think you need "something" to treat your depression, don’t waste your time with over the counter remedies (sleep medications, teas, herbs); talk with your primary care doctor.
Some patients struggle to make improvements in therapy until their medication takes effect. For example, if the patient is very depressed, they may accidentally sleep all day and miss their therapy appointment. It can be helpful to have the support, monitoring, and encouragement of a psychologist/therapist while adjusting to medications or when working on discontinuing medications. Oftentimes depressed patients can “relapse” into depression when discontinuing medication because they haven’t worked with a therapist to develop the coping strategies and lifestyle behaviors that sustain their depression recovery.
All blog posts from Dr. Soo Hoo are provided for educational and informational purposes only. As Dr. Soo Hoo is a licensed clinical and health psychologist, we must make it clear that nothing on the blog is intended to constitute medical or psychological advice, consultation, recommendation, diagnosis, or treatment. If you are concerned about your health, please seek appropriate care in your area.