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A Blood Test May Help Pinpoint the Right Antidepressant for You

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When doctors determine the best medication for a person with depression, they generally rely upon little more than guesswork and patient self-reports, due to insufficient medical evidence. Research out of UT Southwestern Medical Center (UTSMC) previously suggested that such practices were insufficient, and a new study, published in Psychoneuroendocrinology, provides additional diagnostic information that may change the way depression is treated.

The research team drew upon a large body of research that links low levels of inflammation in the body with depression. They say a blood test for an inflammatory biomarker, known as C-reactive protein (CRP), can significantly improve the success rate of two common antidepressants for depressed patients.

Lead author Madhukar Trivedi, a professor of psychiatry at UTSMC and director of the Center for Depression Research and Clinical Care, says doctors typically pick an antidepressant for their patients in one of three ways: personal experience; matching the perceived benefits of one drug with a certain type of patient’s needs; or having the patient pick a drug by ruling out the unwanted side effects of other drugs. “There isn’t a strong evidence base to support one way [of choosing an antidepressant] over another,” he tells mental_floss.

Trivedi says that because many doctors are pressed for time and overloaded with patients, they don't thoroughly address a depressed patient’s needs. “If you have diabetes, the doctor spends a lot of time explaining that it’s a serious illness—there are consequences for ignoring it, and there are treatments you need to do. In depression, that does not happen as much. Patient engagement is not that strong,” he says.

Trivedi led a landmark study more than a decade ago that revealed how serious the medication problem is: Up to one-third of depressed patients don’t see an improvement in their first month of medication, and approximately 40 percent of people who take antidepressants quit within the first three months.

This failure rate is exacerbated by the lingering social stigma accompanying the illness. “It is not fashionable to say, ‘I have depression,’ so people around you may put in their uninformed advice … 'Just go for a walk,' or 'Why are you depressed?'” says Trivedi.

The CRP blood test is traditionally used as a measure of inflammation for such diseases as cardiovascular disease, diabetes, and rheumatoid arthritis, among others, where doctors are looking for high levels of C-reactive protein—approximately 3 to 5 milligrams per blood liter. In the new study, which Trivedi refers to as a “secondary analysis” of a study he led in 2011 (the Co-MED trial), he says, “Our hypothesis was that for depression there may be stress related inflammation in lower levels.”

Trivedi’s lab measured depression remission rates of 106 patients, culled from 440 patients involved in the 2011 study, each of whom had given blood samples. Fifty-one of them had been prescribed only escitalopram (Lexapro), while 55 of them had been prescribed escitalopram plus bupriopion (Wellbutrin), both commonly prescribed SSRI antidepressant drugs.

After analyzing blood samples, the researchers found that for patients whose CRP levels were less than 1 milligram per liter of blood, escitalopram alone was more effective—patients experienced a 57 percent remission rate of their depression versus 30 percent on the other drug. For patients with higher CRP levels, escitalopram plus bupropion was more effective. These patients experienced a 51 percent remission rate, compared to 33 percent on only escitalopram.

Not only do these SSRI antidepressant drugs promote higher levels of retention of the “feel good” neurotransmitters serotonin and dopamine, they trigger an immune response that blocks inflammatory molecules called cytokines.

“The magnitude of the effect was really thrilling,” Trivedi says. “The bottom line in depression is we have not had objective tests that help us with any component of diagnosis or treatment matching—and this is a very solid first step.”

His next step will be to do a clinical trial in which researchers will go to primary care practices and randomize patients, so that half of the participants will get “the best care the provider is willing to do,” he says, and the other half will do the blood test and then get matched with one of the two drug approaches. “We want to show that if you have the treatment matching based on the blood tests, that group of patients will have significantly better outcomes than those who do usual care.”

He hopes that other studies will use the CRP test with other antidepressant drugs, as well. “It’s not a perfect solution for 100 percent of patients, but it helps.”

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More Studies See Links Between Alzheimer's and Herpes
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Although it was discovered in 1906, Alzheimer’s disease didn’t receive significant research attention until the 1970s. In 1984, scientists identified the plaque-like buildup of amyloid beta proteins in brain tissue that causes nerve damage and can lead to symptoms like memory loss, personality changes, and physical debility.

Now, researchers are learning why amyloid beta tends to collect in brain tissue like barnacles on a ship. It might not be rallying expressly to cause damage, but to protect the brain from another invader: the herpes simplex virus.

As The Atlantic recently noted, a number of studies have strengthened the notion that amyloid beta activity is working in response to herpes, the virus that travels along nerve pathways and typically causes cold sores around the mouth (HSV-1) or genitals (HSV-2). In a study involving mice, those engineered to produce more amyloid beta were more resistant to the herpes virus than those who were not.

But when too much amyloid beta is produced to combat the virus, the proteins can affect the brain’s neurons. And while herpes tends to target specific pathways in the body that result in external sores, it’s possible that the virus might act differently in an older population that is susceptible to more widespread infection. Roughly half of adults under age 50 in the U.S. are infected with HSV-1 and 12 percent with HSV-2, which suggests that a large swath of the population could be vulnerable to Alzheimer's disease. Two other strains of the virus, HHV-6A and HHV-7, have also been found to be more common in the brains of deceased Alzheimer’s patients than in the general population.

More research will be needed to further understand the possible relationship between the two. If more findings support the theory, then it’s possible that antiviral drugs or vaccines targeting herpes might also reduce the chances of amyloid beta buildup.

[h/t Atlantic]

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Heatwaves Can Affect Your Ability to Think Clearly and Make Decisions
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Dehydration and body odor aren't the only things to hate about oppressive heat. According to new research reported by The Guardian, living through a heatwave without relief hampers your ability to think quickly and clearly.

For their study, published recently in PLOS Medicine, researchers at the Harvard T.H. Chan School of Public Health tested the mental performance of 44 students during a heatwave in Boston in 2016. Roughly half the students were living in newer dorm buildings with central AC, with the other half living in older dorms without it.

Over 12 days, researchers had participants take cognition tests on their phones immediately after waking up. The students living without AC took about 13 percent longer to respond to the questions and their answers were about 13 percent less accurate.

The results indicate that even if high temperatures don't pose an immediate threat to someone's health, they can impair them in other ways. “Most of the research on the health effects of heat has been done in vulnerable populations, such as the elderly, creating the perception that the general population is not at risk from heat waves,” Jose Guillermo Cedeño-Laurent, research fellow at Harvard Chan School and lead author of the study, said in a statement. “Knowing what the risks are across different populations is critical considering that in many cities, such as Boston, the number of heat waves is projected to increase due to climate change.”

Summers are gradually becoming hotter and longer in Boston—a trend that can be observed throughout most of the rest of the world thanks to the rising temperatures caused by human activity. In regions with historically cold winters, like New England, many buildings, including Harvard's oldest dorms, are built to retain heat, which can extend the negative effects of a heat wave even as the weather outside starts to cool. If temperatures continue to rise, we'll have to make a greater effort to keep people cool indoors, where American adults spend 90 percent of their time.

Our thinking isn't the only thing that suffers in the stifling heat. A study published last year found that hot weather does indeed make you crankier—which may not be as bad as bombing a test, but it's not exactly not fun for the people around you.

[h/t The Guardian]

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