In recent blog entries, we've discussed research that's linked gene variations with medications in order to determine if they'll be safe and effective for individuals with depression.

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The study of these relationships is referred to as psychiatric pharmacogenomics. These aren't tests to determine whether someone is depressed or not. As some of you pointed out, after years of suffering, the diagnosis of depression is not the issue.

The important new development is trying to find an effective treatment. While single genes such as the serotonin transporter gene provide us with some clues, there are still other genes that need to be discovered in order to be able to make better predictions than we can today.

In the past year, three large studies have been conducted to explore possible new genes associated with a better outcome. They include a study in England that found a gene called interleukin-2 was associated with a response to Celexa. However, studies in Germany and the United States didn't confirm this finding.

At Mayo Clinic, we're conducting a similar study to try to identify more gene variants so that we can make better predictions of response to treatment. Another goal is to find new genes that are associated with adverse effects. While many adverse effects are associated with antidepressant medications, one of the most serious is "activating" an episode of mania in someone who's previously not experienced mania.

Another major concern is that sometimes antidepressant medication seems to aggravate suicidal thoughts.  Progress is being made in using genomic testing to be able to identify who may be more likely to develop these problems.

One of the greatest motivations for finding new genes associated with medication response is that gene variation may give us new clues to help us develop new medications for depression — given that at least one in five of you with depression don't respond to any of the drugs currently available.

Helping you if you have treatment resistant depression is a critically important priority for research. Please share your thoughts.

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Pharmacogenomics is a new field of study in medicine. It involves the identification of genetic variations that predict the response of a patient to a medication. Pharmacogenomics is relevant for all types of drugs such as medications for asthma or hypertension. It's now possible to use pharmacogenomic testing to help select an antidepressant.

In a previous blog, I discussed the relationship between a variant of the serotonin transporter gene and vulnerability to developing depression when faced with severe stress. If you have the more active form of this gene, you're less likely to develop depression even if you find yourself in a stressful situation. However, if you have the more active form of this gene and do become depressed, you're more likely to get better if you take a selective serotonin reuptake inhibitor (SSRI) antidepressant like Prozac (fluoxetine), Paxil (paroxetine), or Celexa (citalopram).

The probability of a good response to an SSRI is particularly high if you identify yourself as being "white." This suggests that other gene variations that are more common in patients of European ancestry may also influence the response of these patients to SSRI's.

For several years, it's been known that patients with the more active form of the serotonin transporter gene are more likely to respond to SSRI treatment. However, it's only been possible to test patients to see whether they have a more or less active form of this gene for the past three years. Based on the results of this pharmacogenomic testing, a psychiatrist is now able to develop a better understanding of what the probability will be for a specific patient achieving a good clinical outcome. The primary goal of testing is simply to be able to avoid side effects and identify an effective antidepressant medication more quickly.

To be able to get an even more accurate prediction of response, it will ultimately be necessary to test more than any one single gene as many genes influence the probability of responding to treatment. As testing becomes more sophisticated, there's every reason to believe that treatment outcomes will continue to improve. For many of you struggling with depression, the fact that there are now many researchers working to better understand antidepressant medication response should provide some hope.

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This campus in Jefferson, Arkansas, houses all National Center for Toxicological Research operations, as well as the Arkansas Regional Laboratories, another FDA facility. For more photos of NCTR, visit Flickr.

NCTR researchers Dan Buzatu (right) and Jon Wilkes invented the Rapid-B system to detect live pathogens in foods. For more photos of NCTR, visit Flickr.

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A federal research center born in the Cold War era is celebrating its 40th birthday and its reputation as one of the world’s premier science centers.

The National Center for Toxicological Research (NCTR) is marking its anniversary by formalizing a partnership with the state of Arkansas to create a virtual Center for Regulatory Science. The center’s goals will include modernizing this field of research to bring safer products to the market faster, and increasing the understanding of the potential toxicity of nanotechnology-based products.

But all of NCTR’s work, which spans many fields of science and includes a smorgasbord of new technologies, is really about regulatory science, explains Center Director William Slikker, Jr., Ph.D. The center’s focus is on both the development of new approaches to evaluating the safety of products regulated by the Food and Drug Administration (FDA) and the creation of data sets that substantiate and guide regulatory decisions, he says.

NCTR researchers often study a product before it’s even gone through clinical trials. At other times, they study products that have been around a long time but have unforeseen qualities. No matter what the product or health issue, Slikker says, “We develop data to fill the knowledge gap.”

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In 1971, President Richard Nixon announced the establishment of the National Center for Toxicological Research on 500 acres in Jefferson, Arkansas. The site was once part of the U.S. Army’s Pine Bluff Arsenal but when President Nixon ordered the creation of this new center, it got a new home—the FDA.

NCTR’s initial mission was to study the effects of toxic chemicals on people and their environment. In the 40 years that have followed, NCTR has established itself as an internationally renowned research center, one that studies toxicity in chemicals, drugs and food, in addition to identifying the biomarkers for terrorism. The center studies human susceptibility to toxicants and the risk of disease. Toxicants are chemical, biological or physical agents that can be harmful to people, plants and animals.

The multidisciplinary teams of researchers—partnering with colleagues in other government agencies, industry and academia—also tackle a spectrum of personal and public health issues, including those affecting women and minorities in particular, as well as foodborne pathogens, and personalized nutrition and medicine.

The center has more than 500 scientists and other personnel in 30 buildings, in addition to the students, postdoctoral fellows, visiting scientists and FDA staff who come to NCTR to learn new technologies. “We’ve trained hundreds of individuals over the years,” says Slikker.

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“An important part of modernizing the FDA ... to better protect and promote the public health.”

To celebrate its birthday, FDA and NCTR are taking that research another big step further with the signing of an agreement with the State of Arkansas to create the Center of Excellence for Regulatory Science.

Slikker explained that the agreement is, in a sense,  a formalization of NCTR’s long association with researchers at the University of Arkansas for Medical Sciences and other state universities and institutions. There will be a particular focus on the study of the safety and efficacy of nanotechnology, he says.

The center is virtual in the sense that its work will be conducted in both state and federal facilities. There will be an expanded sharing of resources, facilities and education initiatives that target both students and members of the public.

FDA Commissioner Margaret A. Hamburg, M.D.,  calls the agreement with Arkansas “an important part of modernizing the FDA through the leveraging of intellectual, human and financial resources to better protect and promote the public health.”

Beyond this, NCTR has developed technologies that could one day transform healthcare. They include:

RAPID-B, a portable system that can instantly detect live pathogens (infectious agents that can cause disease)—such as E. coli 0157, Salmonella and Listeria. This can be used for on-site surveillance of food-producing facilities and for the detection of potential contamination of biological cells and tissues.Bioinformatics, the use of computers and math to answer questions about biology. In general, an example of this technology would be software tools that search for certain properties within DNA sequences. At  NCTR, teams of scientists from academia, industry and the government have been working together to create the standards, approaches and bioinformatic tools that will enable researchers to mine rich fields of biological data.Improvements in scanning devices—noninvasive magnetic resonance spectroscopy and MicroPET—to provide informative, translatable and much lower-risk diagnostics.Nanotechnology in cancer therapy that could make it possible to target difficult-to-treat or inoperable cancers.

And there’s promising research underway in the area of personalized medicine, says Slikker. “How do you deal with large data sets and try to develop safety information that’s important to the individual—that’s personalized? This is really exciting."

This article appears on FDA's Consumer Updates page, which features the latest on all FDA-regulated products.