Do antidepressants impair the ability to extinguish fear?

Answers from a new study in Biological Psychiatry

2013-06-10

(Press-News.org) An interesting new report of animal research published in Biological Psychiatry suggests that common antidepressant medications may impair a form of learning that is important clinically.

Selective serotonin reuptake inhibitors, commonly called SSRIs, are a class of antidepressant widely used to treat depression, as well as a range of anxiety disorders, but the effects of these drugs on learning and memory are poorly understood.

In a previous study, Nesha Burghardt, then a graduate student at New York University, and her colleagues demonstrated that long-term SSRI treatment impairs fear conditioning in rats. As a follow-up, they have now tested the effects of antidepressant treatment on extinction learning in rats using auditory fear conditioning, a model of fear learning that involves the amygdala. The amygdala is a region of the brain vitally important for processing memory and emotion.

They found that long-term, but not short-term, SSRI treatment impairs extinction learning, which is the ability to learn that a conditioned stimulus no longer predicts an aversive event.

"This impairment may have important consequences clinically, since extinction-based exposure therapy is often used to treat anxiety disorders and antidepressants are often administered simultaneously," said Dr. Burghardt. "Based on our work, medication-induced impairments in extinction learning may actually disrupt the beneficial effects of exposure-therapy."

This finding is consistent with the results of several clinical studies showing that combined treatment can impede the benefits of exposure therapy or even natural resilience to the impact of traumatic stress at long-term follow-up.

The authors also suggest a mechanism for this effect on fear learning. They reported that the antidepressants decreased the levels of one of the subunits of the NMDA receptor (NR2B) in the amygdala. The NMDA receptor is critically involved in fear-related learning, so these reductions are believed to contribute to the observed effects.

Dr. John Krystal, Editor of Biological Psychiatry, commented, "We know that antidepressants play important roles in the treatment of depression and anxiety disorders. However, it is important to understand the limitations of these medications so that we can improve the effectiveness of the treatment for these disorders."

### The article is "Chronic Antidepressant Treatment Impairs the Acquisition of Fear Extinction" by Nesha S. Burghardt, Torfi Sigurdsson, Jack M. Gorman, Bruce S. McEwen, and Joseph E. LeDoux (doi: 10.1016/j.biopsych.2012.10.012). The article appears in Biological Psychiatry, Volume 73, Issue 11 (June 1, 2013), published by Elsevier.

Notes for Editors Full text of the article is available to credentialed journalists upon request; contact Rhiannon Bugno at +1 214 648 0880 or Biol.Psych@utsouthwestern.edu. Journalists wishing to interview the authors may contact Nesha S. Burghardt at nsb2113@columbia.edu.

The authors' affiliations, and disclosures of financial and conflicts of interests are available in the article.

John H. Krystal, M.D., is Chairman of the Department of Psychiatry at the Yale University School of Medicine and a research psychiatrist at the VA Connecticut Healthcare System. His disclosures of financial and conflicts of interests are available here.

About Biological Psychiatry Biological Psychiatry is the official journal of the Society of Biological Psychiatry, whose purpose is to promote excellence in scientific research and education in fields that investigate the nature, causes, mechanisms and treatments of disorders of thought, emotion, or behavior. In accord with this mission, this peer-reviewed, rapid-publication, international journal publishes both basic and clinical contributions from all disciplines and research areas relevant to the pathophysiology and treatment of major psychiatric disorders.

The journal publishes novel results of original research which represent an important new lead or significant impact on the field, particularly those addressing genetic and environmental risk factors, neural circuitry and neurochemistry, and important new therapeutic approaches. Reviews and commentaries that focus on topics of current research and interest are also encouraged.

Biological Psychiatry is one of the most selective and highly cited journals in the field of psychiatric neuroscience. It is ranked 5th out of 129 Psychiatry titles and 16th out of 243 Neurosciences titles in the Journal Citations Reports® published by Thomson Reuters. The 2011 Impact Factor score for Biological Psychiatry is 8.283.

About Elsevier Elsevier is a world-leading publisher of scientific, technical and medical information products and services. The company works in partnership with the global science and health communities to publish more than 2,000 journals, including The Lancet and Cell, and close to 20,000 book titles, including major reference works from Mosby and Saunders. Elsevier's online solutions include SciVerse ScienceDirect, SciVerse Scopus, Reaxys, MD Consult and Nursing Consult, which enhance the productivity of science and health professionals, and the SciVal suite and MEDai's Pinpoint Review, which help research and health care institutions deliver better outcomes more cost-effectively.

A global business headquartered in Amsterdam, Elsevier employs 7,000 people worldwide. The company is part of Reed Elsevier Group PLC, a world-leading publisher and information provider, which is jointly owned by Reed Elsevier PLC and Reed Elsevier NV. The ticker symbols are REN (Euronext Amsterdam), REL (London Stock Exchange), RUK and ENL (New York Stock Exchange).

ELSE PRESS RELEASES FROM THIS DATE:

Treatment of mental illness lowers arrest rates, saves money

2013-06-10

Research from North Carolina State University, the Research Triangle Institute (RTI) and the University of South Florida shows that outpatient treatment of mental illness significantly reduces arrest rates for people with mental health problems and saves taxpayers money. "This study shows that providing mental health care is not only in the best interest of people with mental illness, but in the best interests of society," says Dr. Sarah Desmarais, an assistant professor of psychology at NC State and co-author of a paper describing the research. The researchers wanted ...

How Archaea might find their food

2013-06-10

The microorganism Methanosarcina acetivorans lives off everything it can metabolize into methane. How it finds its sources of energy, is not yet clear. Scientists at the Ruhr-Universität Bochum together with colleagues from Dresden, Frankfurt, Muelheim and the USA have identified a protein that might act as a "food sensor". They characterized the molecule in detail and found both similarities and differences to the system that is responsible for the search for food in bacteria. The team reports in the Journal of Biological Chemistry. MsmS has a different function to that ...

Eww! Only 5 percent of us wash hands correctly

2013-06-10

VIDEO: A study by Michigan State University researchers found that only 5 percent of people who used the bathroom washed their hands long enough to kill the germs that can cause... Click here for more information. EAST LANSING, Mich. — Remember Mom's advice about washing your hands thoroughly after using the restroom? Apparently not. A new study by Michigan State University researchers found that only 5 percent of people who used the bathroom washed their hands long ...

Split liver transplants for young children proven to be as safe as whole organ transplantation

2013-06-10

Boston, Mass.— A new study shows that when a liver from a deceased adult or adolescent donor is split into two separate portions for transplantation—with the smaller portion going to a young child and the larger to an adult—the smaller portion used for the child will last just as long as if the child had received a whole organ from a donor close to his size. The data, collected and analyzed by a team led by Boston Children's Hospital researchers Heung Bae Kim, MD, and Ryan Cauley, MD, MPH, was published online in Liver Transplantation, a journal of the American Association ...

Research shows river dredging reduced fish numbers, diversity

2013-06-10

Comparing dredged and undredged sections of the Allegheny River, reduced populations of fish and less variety of aquatic life occurred in areas where gravel extraction took place, according to researchers in Penn State's College of Agricultural Sciences,. The researchers investigated navigation pools 7 and 8 near Kittanning and Templeton and published their results in the journal Freshwater Biology. "Understanding and untangling the complex effects of human activities on aquatic ecosystems present a challenge to ecologists and resource managers," said lead investigator ...

Mysterious monument found beneath the Sea of Galilee

2013-06-10

The shores of the Sea of Galilee, located in the North of Israel, are home to a number of significant archaeological sites. Now researchers from Tel Aviv University have found an ancient structure deep beneath the waves as well. Researchers stumbled upon a cone-shaped monument, approximately 230 feet in diameter, 39 feet high, and weighing an estimated 60,000 tons, while conducting a geophysical survey on the southern Sea of Galilee, reports Prof. Shmulik Marco of TAU's Department of Geophysics and Planetary Sciences. The team also included TAU Profs. Zvi Ben-Avraham ...

People are overly confident in their own knowledge, despite errors

2013-06-10

Overprecision — excessive confidence in the accuracy of our beliefs — can have profound consequences, inflating investors' valuation of their investments, leading physicians to gravitate too quickly to a diagnosis, even making people intolerant of dissenting views. Now, new research confirms that overprecision is a common and robust form of overconfidence driven, at least in part, by excessive certainty in the accuracy of our judgments. The research, conducted by researchers Albert Mannes of The Wharton School of the University of Pennsylvania and Don Moore of the Haas ...

How cells get a skeleton

2013-06-10

The mechanism responsible for generating part of the skeletal support for the membrane in animal cells is not yet clearly understood. Now, Jean-François Joanny from the Physico Chemistry Curie Unit at the Curie Institute in Paris and colleagues have found that a well-defined layer beneath the cell outer membrane forms beyond a certain critical level of stress generated by motor proteins within the cellular system. These findings, which offer a new understanding of the formation of this so-called cortical layer, have just been published in EPJ E. Active gels are ideal ...

When will my computer understand me?

2013-06-10

It's not hard to tell the difference between the "charge" of a battery and criminal "charges." But for computers, distinguishing between the various meanings of a word is difficult. For more than 50 years, linguists and computer scientists have tried to get computers to understand human language by programming semantics as software. Driven initially by efforts to translate Russian scientific texts during the Cold War (and more recently by the value of information retrieval and data analysis tools), these efforts have met with mixed success. IBM's Jeopardy-winning Watson ...

Frequent binge drinking is associated with insomnia symptoms in older adults

2013-06-10

DARIEN, IL – A new study suggests that frequent binge drinking is associated with insomnia symptoms in older adults. Results show that overall, 26.2 percent of participants had two or less binge drinking days per week, on average, and 3.1 percent had more than two days per week, on average. After adjustment for demographic variables, medical conditions, and elevated depressive symptoms, participants who binged on an average of more than two days a week had an 84 percent greater odds of reporting an insomnia symptom compared to non-binge drinkers. "It was somewhat surprising ...

Team of Prof. Woo Young Jang Department of Orthopedic Surgery, KU Anam Hospital wins the Best Paper Award from the Korean Musculoskeletal Tumor Society

Do antidepressants impair the ability to extinguish fear?

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: