Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Brain images reveal effects of antidepressants

06.02.2003


The experiences of millions of people have proved that antidepressants work, but only with the advent of sophisticated imaging technology have scientists begun to learn exactly how the medications affect brain structures and circuits to bring relief from depression.



Researchers at the University of Wisconsin-Madison and UW Medical School recently added important new information to the growing body of knowledge. For the first time, they used functional magnetic resonance imaging (fMRI)--technology that provides a view of the brain as it is working--to see what changes occur over time during antidepressant treatment while patients experience negative and positive emotions.

The study appears in the January issue of the American Journal of Psychiatry. UW psychology professor Richard Davidson, Ph.D., psychiatry department chair Ned Kalin, MD, research associate William Irwin and research assistant Michael Anderle were the authors.


The researchers found that when they gave the antidepressant venlafaxine (Effexor(r)) to a small group of clinically depressed patients, the drug produced robust alterations in the anterior cingulate. This area of the brain has to do with focused attention and also becomes activated when people face conflicts. Unexpectedly, the changes were observed in just two weeks.

"Conducting repeated brain scans in these patients allowed us to see for the first time how quickly antidepressants work on brain mechanisms," said Davidson, who also is director of the W. M. Keck Laboratory for Functional Brain Imaging and Behavior, where imaging for the study took place. He noted that the findings were surprising because patients don’t usually begin noticing mood improvements until after they have been taking antidepressants for three to five weeks.

The researchers also found that while the depressed patients displayed lower overall activity in the anterior cingulate than non-depressed controls, those depressed patients who showed relatively more activity before treatment responded better to the medication than those with lower pre-treatment activity. This kind of information may be extremely useful to clinicians someday, Kalin said.

"We expect that physicians in the future will be able to predict which patients will be the best candidates for antidepressants simply by looking at brain scans that reveal this type of pertinent information," said Kalin, who also is director of the HealthEmotions Research Institute, where scientists concentrate on uncovering the scientific basis of linkages between emotions and health. One third of all patients treated with antidepressants do not respond to them, and of those that do, only about 50 percent get completely better, he added.

Virtually all previous studies analyzing brain activity in depressed people used PET (positron emission tomography) and SPECT (single photon emission computed tomography) technology. With these imaging systems scientists were not able to obtain pictures with the same resolution as that which is now obtainable with fMRI, which provides a "working snapshot" of the brain.

The Wisconsin team used fMRI’s capability to capture brain activity as it occurred to record subjects’ reactions as they viewed pictures designed to stimulate negative and positive emotions.

"We believe that we can uncover the best indicators of treatment changes when we present research subjects these emotion challenges," said Davidson. "The pictures activate the individual circuits that underlie different kinds of emotional responses."

UW emotions researchers have been using fMRIs with emotion-challenging pictures for several years in an effort to understand normal and abnormal brain responses to a range of emotions. They theorize that in depressed people, reactions to negative emotions are similar to, but more exaggerated than, reactions that non-depressed people have, and that the reactions may be more difficult to turn off.

"We all experience some sadness from time to time, but in depression, the responses may be sustained and out of context," said psychiatrist Kalin.

With the HealthEmotions Research Institute, the Keck Laboratory for Functional Brain Imaging and Behavior and the Laboratory for Affective Neuroscience, UW is home to a critical mass of some of the foremost emotions researchers in the world.


###
CONTACT: Dian Land, 608-263-9893, dj.land@hosp.wisc.edu; Lisa Brunette, 608-263-5830, la.brunette@hosp.wisc.edu.

Dian Land | EurekAlert!
Further information:
http://www.wisc.edu/

More articles from Health and Medicine:

nachricht Chances to treat childhood dementia
24.07.2017 | Julius-Maximilians-Universität Würzburg

nachricht World first: Massive thrombosis removed during early pregnancy
20.07.2017 | Universitätsspital Bern

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

Ultrathin device harvests electricity from human motion

24.07.2017 | Power and Electrical Engineering

Scientists announce the quest for high-index materials

24.07.2017 | Materials Sciences

ADIR Project: Lasers Recover Valuable Materials

24.07.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>