New evidence puts into doubt the long-held depression belief

New evidence puts into doubt the long-standing belief that a deficiency in serotonin - a chemical messenger in the brain - plays a central role in depression. In the journal ACS Chemical Neuroscience, scientists report that mice lacking the ability to make serotonin in their brains (and thus should have been "depressed" by conventional wisdom) did not show depression-like symptoms.

Donald Kuhn and colleagues at the John D. Dingell VA Medical Center and Wayne State University School of Medicine note that depression poses a major public health problem. More than 350 million people suffer from it, according to the World Health Organization, and it is the leading cause of disability across the globe. In the late 1980s, the now well-known antidepressant Prozac was introduced. The drug works mainly by increasing the amounts of one substance in the brain - serotonin. So scientists came to believe that boosting levels of the signaling molecule was the key to solving depression. Based on this idea, many other drugs to treat the condition entered the picture. But now researchers know that 60 to 70 percent of these patients continue to feel depressed, even while taking the drugs. Kuhn's team set out to study what role, if any, serotonin played in the condition.

To do this, they developed "knockout" mice that lacked the ability to produce serotonin in their brains. The scientists ran a battery of behavioral tests.

Interestingly, the mice were 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. Also, a subset 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. These results could dramatically alter how the search for new antidepressants moves forward in the future, the researchers conclude.

Comments

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment
Post

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.

You might also like...
Research highlights immune system's role in depression