Unless your newsfeed features obscure psychiatry and psychology news, UK news, or the very limited US news coverage of the July 2022 publication of “The serotonin theory of depression: A systemic umbrella review of the evidence,” in the Journal of Molecular Psychiatry, you might not have heard this news. In a sweeping meta-analysis addressing six serotonin-based hypotheses and multiple studies, one of over 150,000 people, the conclusion has been drawn that, verifying what the senior author of the article, Dr. Mark Horowitz, noted is “known in academic circles, that no good evidence has ever been found of low serotonin in depression (Medscape, July 22, 2022).” The evidence does indicate, in some studies, that long-term use of some antidepressants can lead to lower serotonin levels, just as long-term use of drugs that boost dopamine (amphetamines, for example) can ultimately lead to depletion and insufficiency of that neurotransmitter.
To repeat, in the academic world, it has long known there is really no substantive evidence linking low serotonin levels to depression. This is similar to the academic knowledge that marijuana, especially in its modern, heightened THC formulas, is a dangerous road to sometimes unrelenting anxiety or even psychosis. However, since science is hard and so often inconvenient, these particular unpopular truths have usually been ignored. About one in six Americans, and about one in six English adults, are on antidepressants. Yet the science says the rationale for these drugs – that they will fix a chemical imbalance in the brain – does not stand. The science does seem to indicate a placebo effect, as well as some people experiencing a numbing of emotional pain, which might be sufficient to begin the work of the changes necessary to heal from depression. The researchers are quick to note that no one should stop these medications quickly; cessation ought to be done slowly, with medical supervision, because of the risk of physical and psychological ill effects during withdrawal.
Depression, as Dr. Horowitz’ team and countless other researchers and clinicians have long asserted, is a complex experience of physical, emotional, cognitive and social aspects. It is also a rather fluid diagnosis, encompassing, as it does now in the current diagnostic manual, almost any two-week period in which sufficient symptoms are met, even when life’s events make it a completely normal response. As I have noted in other articles, the grief exclusion for depression has been eliminated, for example. Are we, therefore, to believe that, once someone you love dies, you develop a potentially lifelong brain disease in which one neurotransmitter (among many) suddenly goes haywire? Or is it feasible that death, or profound injury, or the loss of a job or home or friendship, etc., could cause sadness, physical pain and fatigue, and a tendency to withdraw from the very activities and relationships that could bolster recovery?
One of the interesting aspects of this study was its analysis of the very popular genetic explanation, a sort of, “It runs in my family,” explanation for depression. Besides the scientific analysis of the large body of research indicating that that while a very small, initial study hinted this may be the case, the much larger research studies indicate it is not. Of course, there is more to “running in the family” than genes. Some of this may be impacted prenatally via epigenetics, which helps tell which genes to turn “up” or “down” (a grotesque oversimplification; sorry) depending on environmental stressors such as severe poverty and want of food. Then our families teach us whether the world is a safe place or not, and whether to take risks or not. Optimally, families teach us we are worthwhile, and how to make connections and corrections in relationships. They set a life pattern in place that may ses us up for long-term healthy habits, or inflict a neglected or violent childhood that results in shortened telomeres and the prospect of an unhealthy and too-short adulthood. If the family fights dirty, abuses substances and one another, is rejected by the community via being fired repeatedly from jobs, ostracized by neighbors, and disliked by peers, the children will grow up to be unlikeable, rejected, angry and depressed adults. There need not be any genetic component for this to be the case.
This type of adult will need to learn to heal wounds, how to develop a sense of purpose and meaning, and the cognitive skills to overcome depression. The latter includes developing the skill of interrupting and redirecting rumination, challenging and changing unhealthy thought and behavior patterns and thus changing emotions, and improving the skill of being in the moment, or, as Dr. Stephen Hayes has written, “Get out of your head and into your life.”
There are biological factors at play; anyone who believes they are suffering from depression ought to have a full physical exam, including bloodwork, to rule out medical causes for many of the symptoms of depression. Good guidance on nutrition, sleep, exercise and natural light exposure are all in the physical realm of helping, and deficiencies in any of these areas may be sufficient to trigger the low mood, lack of energy, erratic eating and sleeping identified with depression.
There is, as can be seen, nothing here that is so complex that it is beyond the average person’s ability to understand and do. For most of human history, the rhythm of sleep, hard work, natural light, meaningful connections with others and a strong accession to the transcendent provided a milieu in which profound suffering had both meaning and support. Our lives were designed for mental health. This, alone, is so reassuring and empowering that one would think that this simple, ancient recipe for mental health would have never been relegated to a supporting role. Unlike the message that your brain is broken and there is nothing to be done except take this pill – which may make you suicidal, or homicidal, or cause tremendous weight gain, sexual difficulties, apathy, or moments of mania – the message of the Horowitz et al research is a hopeful and inspiring one: that it is possible to overcome the depression that threatens to crush your spirit.