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 GLUT5 fluorescent probe fingerprints cancer cells
20.04.2018 | Michigan Technological University

nachricht Scientists re-create brain neurons to study obesity and personalize treatment
20.04.2018 | Cedars-Sinai Medical Center

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: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Getting electrons to move in a semiconductor

25.04.2018 | Physics and Astronomy

Reconstructing what makes us tick

25.04.2018 | Physics and Astronomy

Cheap 3-D printer can produce self-folding materials

25.04.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>