Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New brain-chemistry differences found in depressed women

08.11.2006
U-M Depression Center study shows alterations in key brain-chemical system involved in responding to stress and regulating emotions

A new brain study finds major differences between women with serious depression and healthy women in a brain-chemical system that's crucial to stress and emotions.

The study adds further evidence that depression has its roots in specific alterations within the brain -- specifically in the endogenous opioid system that is a central part of the brain's natural pain and stress-reduction system. The findings also show significant variation between individuals with depression – variation that seems to be linked to whether or not the patients respond to an antidepressant medication.

The study, performed by researchers at the University of Michigan Medical School affiliated with the U-M Depression Center, is published in the November issue of the Archives of General Psychiatry. It's based on brain imaging, blood chemistry and other data from 14 women with major depression, and 14 healthy women of about the same age and background. The women with depression were not taking antidepressants when the study began.

... more about:
»Emotional »antidepressant »memories »mu-opioid »pain

"This work gives further evidence of individual differences in brain mechanisms that are altered in major depression," says senior author Jon-Kar Zubieta, M.D., Ph.D., the Jenkins Research Professor of Depression and associate professor of psychiatry and radiology. "We found these differences in the response of the endogenous opioid system. Some women, but not others, with major depression, showed exaggerated responses in this system when undergoing an emotional challenge."

That emotional challenge was the summoning of memories of a very sad event in their lives, which the researchers asked the women to recall while they were lying in the positron emission tomography (PET) scanner having their brains imaged. The women recalled the death or serious illness of a friend or family member, a past divorce or breakup with a boyfriend, or other major difficulties. They also had their brains imaged during a neutral emotional state.

Just before the brain scans, the women also had their blood tested to measure levels of two hormones that are released in response to stress. The depressed women were then prescribed an antidepressant drug and reported regularly about their depression symptoms for the next ten weeks. Those whose depression hadn't eased by the end of the first month received a prescription for an increased dose of antidepressant.

"Women who had more pronounced responses in their stress response mechanisms during brain imaging also showed alterations in hormones, like cortisol, that are sometimes over-secreted in depression," Zubieta explains. "In addition, these women responded poorly to treatment with medication."

The research builds on previous studies that found differences in the body's and brain's stress-response system among people with depression. But this is the first time that specific differences in the mu-opioid system have been shown between people with depression and those without.

Zubieta performed the work with former doctoral student, Susan Kennedy, Ph.D., who is first author on the new paper. They used a brain-imaging technique that the U-M team has previously used to see how the brain responds to pain – and to placebo pain treatment.

The technique uses a form of a drug called carfentanil, which binds to the same receptors on the surface of brain cells that brain chemicals called mu-opioids bind to. Mu-opioids, sometimes also called endorphins, reduce or block the spread of messages related to pain, stress and emotional distress between the body and the brain. They have been called the body's "natural painkillers." The drug is modified to allow it to be "seen" by the PET scanner, so that the researchers can create maps of the specific brain areas where the natural mu-opioids are more or less active at any given time.

In the new study, the researchers also found that the mu-opioid system was overactive in women with depression, even at baseline, when they weren't being asked to recall sad memories.

During the "sadness challenge", the non-depressed women did not show any activation of their mu-opioid system, but the depressed women had a significant activation of that system, and the level of that activation correlated with the intensity of their negative emotional state brought on by the sad memories. Among the non-depressed women, the mu-opioid system was actually less active in some parts of the brain than it had been before they recalled sad memories.

The researchers found differences among the depressed women, too, in some areas of the brain. In the rostral anterior cingulate, which is involved in mood regulation and the integration of sensations and emotions, women who later responded to antidepressant treatment had far lower mu-opioid responses than women who did not respond to medication.

The new findings add the mu-opioid system to the list of brain systems that appear to be altered in depression. Others include the corticotrophin-releasing hormone system, and those involved in noradrenaline, dopamine and serotonin production.

"Further research on these differences, and their relationship to patients' responses to various depression treatments, is crucial to the continued improvement in the understanding of depression and the development of better treatment strategies for patients," Zubieta says.

Kara Gavin | EurekAlert!
Further information:
http://www.depressioncenter.org
http://www.umich.edu

Further reports about: Emotional antidepressant memories mu-opioid pain

More articles from Life Sciences:

nachricht Making fuel out of thick air
08.12.2017 | DOE/Argonne National Laboratory

nachricht ‘Spying’ on the hidden geometry of complex networks through machine intelligence
08.12.2017 | Technische Universität Dresden

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

Blockchain is becoming more important in the energy market

05.12.2017 | Event News

 
Latest News

New research identifies how 3-D printed metals can be both strong and ductile

11.12.2017 | Physics and Astronomy

Scientists channel graphene to understand filtration and ion transport into cells

11.12.2017 | Materials Sciences

What makes corals sick?

11.12.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>