Navigation Links
Univ. of MD School of Medicine finds depression stems from miscommunication between brain cells
Date:3/18/2013

A new study from the University of Maryland School of Medicine suggests that depression results from a disturbance in the ability of brain cells to communicate with each other. The study indicates a major shift in our understanding of how depression is caused and how it should be treated. Instead of focusing on the levels of hormone-like chemicals in the brain, such as serotonin, the scientists found that the transmission of excitatory signals between cells becomes abnormal in depression. The research, by senior author Scott M. Thompson, Ph.D., Professor and Interim Chair of the Department of Physiology at the University of Maryland School of Medicine, was published online in the March 17 issue of Nature Neuroscience.

According to the Centers for Disease Control and Prevention, between 2005 and 2008, approximately one in 10 Americans were treated for depression, with women more than twice as likely as men to become depressed. The most common antidepressant medications, such as Prozac, Zoloft and Celexa, work by preventing brain cells from absorbing serotonin, resulting in an increase in its concentration in the brain. Unfortunately, these medications are effective in only about half of patients. Because elevation of serotonin makes some depressed patients feel better, it has been thought for over 50 years that the cause of depression must therefore be an insufficient level of serotonin. The new University of Maryland study challenges that long-standing explanation.

"Dr. Thompson's groundbreaking research could alter the field of psychiatric medicine, changing how we understand the crippling public health problem of depression and other mental illness," says E. Albert Reece, M.D., Ph.D., M.B.A., Vice President for Medical Affairs at the University of Maryland and John Z. and Akiko K. Bowers Distinguished Professor and Dean at the University of Maryland School of Medicine. "This is the type of cutting-edge science that we strive toward at the University of Maryland, where discoveries made in the laboratory can impact the clinical practice of medicine."

Depression affects more than a quarter of all U.S. adults at some point in their lives, and the World Health Organization predicts that by 2020 it will be the second leading cause of disability worldwide. Depression is also the leading risk factor for suicide, which causes twice as many deaths as murder, and is the third leading cause of death for 15-24 year olds.

The first major finding of the study was the discovery that serotonin has a previously unknown ability to strengthen the communication between brain cells. "Like speaking louder to your companion at a noisy cocktail party, serotonin amplifies excitatory interactions in brain regions important for emotional and cognitive function and apparently helps to make sure that crucial conversations between neurons get heard," says Dr. Thompson. "Then we asked, does this action of serotonin play any role in the therapeutic action of drugs like Prozac?"

To understand what might be wrong in the brains of patients with depression and how elevating serotonin might relieve their symptoms, the study team examined the brains of rats and mice that had been repeatedly exposed to various mildly stressful conditions, comparable to the types of psychological stressors that can trigger depression in people.

The researchers could tell that their animals became depressed because they lost their preference for things that are normally pleasurable. For example, normal animals given a choice of drinking plain water or sugar water strongly prefer the sugary solution. Study animals exposed to repeated stress, however, lost their preference for the sugar water, indicating that they no longer found it rewarding. This depression-like behavior strongly mimics one hallmark of human depression, called anhedonia, in which patients no longer feel rewarded by the pleasures of a nice meal or a good movie, the love of their friends and family, and countless other daily interactions.

A comparison of the activity of the animals' brain cells in normal and stressed rats revealed that stress had no effect on the levels of serotonin in the 'depressed' brains. Instead, it was the excitatory connections that responded to serotonin in strikingly different manner. These changes could be reversed by treating the stressed animals with antidepressants until their normal behavior was restored.

"In the depressed brain, serotonin appears to be trying hard to amplify that cocktail party conversation, but the message still doesn't get through," says Dr. Thompson. Using specially engineered mice created by collaborators at Johns Hopkins University School of Medicine, the study also revealed that the ability of serotonin to strengthen excitatory connections was required for drugs like antidepressants to work.

Sustained enhancement of communication between brain cells is considered one of the major processes underlying memory and learning. The team's observations that excitatory brain cell function is altered in models of depression could explain why people with depression often have difficulty concentrating, remembering details, or making decisions. Additionally, the findings suggest that the search for new and better antidepressant compounds should be shifted from drugs that elevate serotonin to drugs that strengthen excitatory connections.

"Although more work is needed, we believe that a malfunction of excitatory connections is fundamental to the origins of depression and that restoring normal communication in the brain, something that serotonin apparently does in successfully treated patients, is critical to relieving the symptoms of this devastating disease," Dr. Thompson explains.


'/>"/>

Contact: Karen Robinson
karobinson@som.umaryland.edu
410-706-7590
University of Maryland Medical Center
Source:Eurekalert

Related medicine news :

1. Mindfulness at school reduces likelihood of depression-related symptoms in adolescents
2. Customizable Rugged iPad Case For Schools Offers Protection and Branding
3. Med School Students Still Get Gifts From Drug Companies: Survey
4. Rugged iPad Case Eliminates Broken Screens for Schools
5. Life Coaching Certification School Holistic Learning Center Releases New Content For Public Viewing
6. Life Coaching Certification School Holistic Learning Center Announces The Distribution Of Self Mastery Product
7. New grant launches initiative to shift how LGBTQ sexuality is discussed in schools
8. The World School of Massage and Holistic Healing Arts to Unveil New Wellness Education and Spa-Massage Program
9. A picture of health in schools
10. Pediatricians Say No to Expulsions, Suspensions at Schools
11. Safety Training Seminars Opens Their 6th Bay Area American Heart Association CPR, BLS and First-aid Certification Training School in Redwood City
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/26/2017)... ... May 26, 2017 , ... via seating ... mesh back 24/7 task chair specifically designed for clinical areas. Genie Copper Mesh ... to partner with Cupron® to provide customers with a game changing chair that ...
(Date:5/26/2017)... ... ... Lowe acts as host and helps educate and inform the public using the “Informed” ... reconnect with America as it explores some of the best places to hike and ... inventive new place for a family vacation, and have discovered hiking. Many will agree ...
(Date:5/26/2017)... ... ... What Happened in the Garden of Eden”: retells the stories of three Bible figures in ... published author, Penelope Colt, mother, trader, horse farmer, artist and a former GM journeyman. ... At six, they moved to Dayton, Ohio, where Penny graduated high school. At ...
(Date:5/24/2017)... New York (PRWEB) , ... May 24, 2017 , ... ... vascular surgery in New York City. He is known for his distinguished ... specialization in vascular surgery, Dr. Benvenisty holds sub-specialty training in treating renovascular disease and ...
(Date:5/24/2017)... Cortland, OH (PRWEB) , ... May 24, 2017 , ... ... in Cortland, OH, can now meet with Dr. Joseph Bedich for a consultation, ... smiles while simultaneously improving their oral health and functionality. , Dr. Bedich ...
Breaking Medicine News(10 mins):
(Date:5/11/2017)... 11, 2017  Thornhill Research Inc. ( ... an $8,049,024 USD five-year, firm-fixed-priced, indefinite-quantity/indefinite-delivery contract by ... Commercial Corporation (CCC) ( Ottawa, Ontario, Canada ... administer general anesthesia to patients requiring emergency medical ... US Marine Corps have been a longtime partner ...
(Date:5/10/2017)... 10, 2017 Radiology has become the number ... have also spiraled to the number one ranking as ... than ever before as the most complete and reliable ... with lower back pain an MRI may confirm a ... pain, resulting in entirely different treatment protocols.  In these ...
(Date:5/9/2017)... JERUSALEM , May 9, 2017  Oramed ... www.oramed.com ), a clinical-stage pharmaceutical company focused on ... today that the Canadian Intellectual Property Office has ... for Oral Administration of Exenatide". The patent covers ... analog. GLP-1 is an incretin hormone ...
Breaking Medicine Technology: