This paper will discuss the article by Moncrieff et al. (2022), which is a systematic umbrella review aimed at evaluating evidence on whether depression is related to low serotonin activity and concentration. The authors justify the need for this review by the fact that, although the theory is widely used in research and clinical practice, there is no comprehensive synthesis of existing evidence. In this paper, I will provide my understanding and opinion of the article. I will argue that the article oversimplifies the causes of depression and the mechanism of action of antidepressants, and it can be misleading for non-professionals.
The article is devoted to the serotonin theory of depression, suggesting that this mental health condition results from a chemical imbalance in the body. According to the authors, this theory has become popular since the 1990s when the Selective Serotonin Reuptake Inhibitor (SSRI) antidepressants came into use (Moncrieff et al., 2022). Further in the article, the authors share their findings that the serotonin theory seems to lack reasonable evidence supporting it. These findings suggest that chemical imbalance is unlikely to be associated with depression. However, depression is a complex disorder that can develop due to a variety of factors. Therefore, by attributing this condition solely to a chemical imbalance or totally discarding the potential influence of neurotransmitters on the development of the disease, one oversimplifies depression.
The serotonin theory of depression is closely related to antidepressants since the advent of SSRIs played a significant role in the popularization of the theory. My understanding of the article is that the researchers linked the effectiveness of antidepressants to the serotonin system. It seems that Moncrieff et al. (2022) explained the wide use of antidepressants for depression by the common belief that these drugs affect serotonin levels in the body or fixed the chemical imbalance in general. Yet, since the researchers found this belief about the association between serotonin and depression to be unproven, they seem to put into question the use of antidepressants. However, as far as I know, antidepressants are widely used because of their effectiveness. Sometimes, they can be the only viable option for people with depression, especially for those in whom this condition is severe. Therefore, although the serotonin theory turns out to lack evidential support, one cannot ignore the effectiveness of antidepressants as shown in clinical trials and in general practice and psychiatry.
Finally, I was particularly drawn to the authors’ claims about the effects of the serotonin theory on people with depression. Moncrieff et al. (2022) say that the popularity of this theory may mislead individuals into thinking that they do not have power over their mood and depression since they are controlled by chemicals in the brain. While this can be true, I believe that when people know that there may be biological reasons for their mental health problems, they are more likely to seek professional help. Moncrieff et al. (2022) also conclude that the belief in the chemical imbalance as a cause of depression may influence people’s decision to start, continue or discontinue the use of antidepressants. I have found this statement troubling because if non-professionals read the article, they may perceive it as a call to discontinue their antidepressant treatment. This would be an undesirable outcome since antidepressants are sometimes the most effective option for treating depression, and their use should not be discouraged only because the serotonin theory was not supported by evidence.
In conclusion, the researchers did a great amount of work synthesizing studies related to the association between serotonin activity and concentration and depression. From this article, I learned that the serotonin theory is important but still lacks empirical support. Yet, in my opinion, the authors seem to simplify the causes of depression by focusing on the chemical imbalance. Finally, the article is not recommended to non-professionals because of possible misunderstanding.
Reference
Moncrieff, J., Cooper, R. E., Stockmann, T., Amendola, S., Hengartner, M. P., & Horowitz, M. A. (2022). The serotonin theory of depression: A systematic umbrella review of the evidence. Molecular Psychiatry, 1-14.