Health and Medical News and Resources

General interest items edited by Janice Flahiff

Depression: An evolutionary byproduct of immune system?

Depression: An evolutionary byproduct of immune system?

From the 3 March 2012 article at Science News Daily

 Depression is common enough — afflicting one in ten adults in the United States — that it seems the possibility of depression must be “hard-wired” into our brains. This has led biologists to propose several theories to account for how depression, or behaviors linked to it, can somehow offer an evolutionary advantage

Some previous proposals for the role of depression in evolution have focused on how it affects behavior in a social context. A pair of psychiatrists addresses this puzzle in a different way, tying together depression and resistance to infection. They propose that genetic variations that promote depression arose during evolution because they helped our ancestors fight infection….

“The basic idea is that depression and the genes that promote it were very adaptive for helping people — especially young children — not die of infection in the ancestral environment, even if those same behaviors are not helpful in our relationships with other people,” Raison says.

Infection was the major cause of death in humans’ early history, so surviving infection was a key determinant in whether someone was able to pass on his or her genes. The authors propose that evolution and genetics have bound together depressive symptoms and physiological responses that were selected on the basis of reducing mortality from infection. Fever, fatigue/inactivity, social avoidance and anorexia can all be seen as adaptive behaviors in light of the need to contain infection, they write.

The theory provides a new explanation for why stress is a risk factor for depression. The link between stress and depression can be seen as the byproduct of a process that preactivates the immune system in anticipation of a wound, they write….

March 5, 2012 Posted by | Consumer Health | , , | Leave a comment

Infections in ICUs Plummeting, Too Many Remain in Hospitals and Dialysis Clinics

Infections in ICUs Plummeting, Too Many Remain in Hospitals and Dialysis Clinics

http://www.cdc.gov/media/releases/2011/p0301_vitalsigns.html

ICUs show that preventing infections is possible; other health care settings must adopt prevention practices

From the press release

The number of bloodstream infections in intensive care unit patients with central lines decreased by 58 percent in 2009 compared to 2001, according to a new CDC Vital Signs report. During these nine years, the decrease represented up to 27,000 lives saved and $1.8 billion in excess health care costs. Bloodstream infections in patients with central lines can be deadly, killing as many as 1 in 4 patients who gets one….

“Preventing bloodstream infections is not only possible, it should be expected. Meticulous insertion and care of the central line by all members of the clinical care team including doctors, nurses and others at the bedside is essential. The next step is to apply what we’ve learned from this to other health care settings and other health care-associated conditions, so that all patients are protected,” said Thomas R. Frieden, M.D., M.P.H., CDC director.

In addition to the ICU findings, the report found that about 60,000 bloodstream infections in patients with central lines occurred in non-ICU health care settings such as hospital wards and kidney dialysis clinics. About 23,000 of these occurred in non-ICU patients (2009) and about 37,000 infections occurred in dialysis clinics patients (2008).

“This reduction is the result of hospital, local, state and national medical and public health efforts focused on tracking infection rates and then using that information to tailor and evaluate prevention programs,” said Denise Cardo, M.D., director of CDC’s Division of Healthcare Quality Promotion. “The report findings point to a clear need for action beyond ICUs. Fortunately, we have a prevention model focused on full collaboration that can be applied broadly to maximize prevention efforts.”

Infections are one of the leading causes of hospitalization and death for hemodialysis patients. At any given time, about 350,000 people are receiving hemodialysis treatment for kidney failure. Seven in 10 patients who receive dialysis begin that treatment through a central line….

March 18, 2011 Posted by | Consumer Health | , , , , , , , | Leave a comment

   

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