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Mice Study Suggests Lack of Serotonin Not Behind Depression

Mice Study Suggests Lack of Serotonin Not Behind Depression

New evidence challenges the conventional wisdom that the brain chemical serotonin is responsible for maintaining mood balance, and that a deficit of serotonin leads to depression.

The causes of depression have long been in dispute, with scientists acknowledging that there is generally no single cause of this common mental illness diagnosis. Many researchers believe it is related to the neurochemistry of the brain, and specific neurotransmitters, such as serotonin.

But the latest research suggests that the serotonin theory of the cause of depression is simplistic and likely false.

In a study, scientists report that mice lacking the ability to make serotonin in their brains did not show depression-like symptoms. Mice are often studied in this manner, because they have simpler biological symptoms than humans, while also being capable of exhibiting symptoms similar to depression in humans.

Donald Kuhn, Ph.D., and colleagues at Wayne State University School of Medicine set out to study what role, if any, serotonin played in the development of depression.

To do this, they developed “knockout” mice that had been genetically altered to prevent the production of serotonin in their brains. Then, scientists ran a battery of behavioral tests on the special mice.

Interestingly, researchers found the mice to be compulsive and extremely aggressive, but didn’t show signs of depression-like symptoms.

Another surprising finding is that when put under stress, the knockout mice behaved in the same way most of the normal mice did. And some of the knockout mice responded therapeutically to antidepressant medications in a similar manner to the normal mice.

These findings further suggest that serotonin is not a major player in the condition, and different factors must be involved, according to the researchers.

The study was a small animal study. Because it was an animal study, it would need to be replicated in humans to determine if its findings hold up.

If the study is replicated, a new approach for the development of antidepressants may be called for.

The study is published in the journal ACS Chemical Neuroscience.

Source: American Chemical Society


Mice Study Suggests Lack of Serotonin Not Behind Depression

Rick Nauert PhD

Rick Nauert, PhDDr. Rick Nauert has over 25 years experience in clinical, administrative and academic healthcare. He is currently an associate professor for Rocky Mountain University of Health Professionals doctoral program in health promotion and wellness. Dr. Nauert began his career as a clinical physical therapist and served as a regional manager for a publicly traded multidisciplinary rehabilitation agency for 12 years. He has masters degrees in health-fitness management and healthcare administration and a doctoral degree from The University of Texas at Austin focused on health care informatics, health administration, health education and health policy. His research efforts included the area of telehealth with a specialty in disease management.

APA Reference
Nauert PhD, R. (2019). Mice Study Suggests Lack of Serotonin Not Behind Depression. Psych Central. Retrieved on November 23, 2020, from
Scientifically Reviewed
Last updated: 2 Oct 2019 (Originally: 28 Aug 2014)
Last reviewed: By a member of our scientific advisory board on 2 Oct 2019
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