Summary of When It Comes to Depression, Serotonin Isn’t the Whole Story

Summary of When It Comes to Depression, Serotonin Isn’t The Whole Story

For decades, mental health professionals have operated under the idea that the cause of depression is a chemical imbalance in the brain, particularly of low serotonin (Spiegel 2012). Even today, this idea that low serotonin causes depression is very popular. According to Alan Frazer, a researcher who studies antidepressants at the University of Texas, San Antonio it may the dominant view of the cause of depression among mental health practitioners. However, among researchers who study depression, this theory of chemical imbalance being the sole cause of depression is falling out of favor. Modern researchers have come to believe it is “much more complicated than that.”

The low serotonin narrative had it’s origin in a psychiatric hospital in Switzerland in the late 1950s, according to Frazer.  At this hospital, a psychiatrist named Roland Kuhn, observed that when depressed patients were given tricyclics, the first antidepressants, they showed a marked improvement in their condition. Researchers did not understand the process by which these tricyclics worked to ameliorate depression until sometime in the 1960s.

In the 1960s, a breakthrough was made in Parkinson’s disease research. The cause of the disease was determined to be a deficiency of to the neurotransmitter dopamine. Frazer believes that scientists researching depression borrowed this idea of a chemical deficiency and applied towards their understanding of depression.

Although scientists had come to accept chemical deficiency as a cause of depression, they had not settled on exactly which chemical until an antidepressant called Prozac was brought to market in the late 1980s. Prozac had very few side effects compared to alternatives at the time which allowed it to quickly become very popular. Prozac worked by targeting the chemical serotonin. Prozac’s popularity allowed the low serotonin narrative to become dominant, despite the lack of research supporting the idea according to Frazer.

Some depression researchers, such as Pedro Delgado, who is the head of the psychiatry department at the University of Texas, believe that they have debunked the idea that low serotonin causes depression. Delgado cites research he performed in the ‘90s as evidence for his position. In this study, serotonin was removed from individuals who were not depressed without causing them to become depressed. Other researchers are reluctant to completely dismiss serotonin’s role in depression and believe that while serotonin levels may not be the primary cause of depression, it does have a measurable effect. On the whole, researchers have come to believe that serotonin is not as important to depression as it was once thought to be. Focus has shifted to other causes, such as genetics.